Zoom lens system

ABSTRACT

In a zoom lens system in which the movement locus of a focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam, and the sensitivity of movement of an image point in association with the movement, in the direction of the optical axis, of the focusing lens unit in infinity and closest in-focus states does not vary so much, the ratio of the amount of rotation for focusing upon focusing from the infinity position to the closest distance position to the amount of rotation for zooming from the wide-angle end to the telephoto end in the focus cam is set to fall within a predetermined range, so that the sensitivity of movement of an image point in association with the movement, in the direction of rotation, of the focusing lens unit satisfies a specific condition.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a zoom lens and, more particularly, to a zoom lens attached to a so-called auto-focusing camera, video camera, or the like, which has a focus detection device, and moves a focusing lens unit in a photographing optical system in accordance with the detected defocus amount.

2. Related Background Art

In recent years, along with the wide spread use of auto-focusing cameras, various focusing systems such as a so-called inner focusing system, rear focusing system, and the like have been examined to make a focusing lens of a zoom lens compact.

However, in general, when a focusing system other than a so-called front focusing system is adopted, the lens driving amount for focusing changes upon a change in focal length. To solve this problem, Japanese Patent Application Laid-Open Nos. 4-293008 and 5-142475 assigned to the same assignee as the present invention proposed a method of realizing a so-called manual focusing operation in a zoom lens having a plurality of lens units including a focusing lens unit having both zooming and focusing functions. In this method, when a predetermined movement locus for zooming is expressed by the amount of movement of the lens units in the direction of the optical axis and the angle of rotation of a rotatable lens barrel, the movement locus of the focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam. With this arrangement, even when the amount of movement for focusing along the optical axis changes depending on the zooming state, the angle of rotation of the rotatable lens barrel for focusing is left unchanged, thus achieving a manual focusing operation.

However, when the above-mentioned zoom lens is applied to an auto-focusing camera system, which comprises focus detection means, storage means for storing the conversion coefficient γ and the correction coefficient ε used for calculating the lens driving amount Δx for focusing the focusing lens unit on the basis of the detected defocus amount ΔBf of a photographing optical system, and calculation means for calculating the lens driving amount Δx for focusing using the defocus amount ΔBf, the conversion coefficient γ, and the correction coefficient ε, problems associated with the storage capacity, calculation error, and the like are posed.

As in Japanese Patent Application Laid-Open Nos. 4-293008 and 5-142475 above, in a zoom lens disclosed in Japanese Patent Application Laid-Open Nos. 57-37307, 57-37308, 63-49715, 63-314511, 3-144411, 3-235908, 3-249717, 4-184402, 4-184403, 4-184404, 4-184405, 4-184406, 4-186207, 4-186208, 7-110446, and the like, in each of which the movement locus of the focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam, the above-mentioned problems concerning the storage capacity, calculation error, and the like have not been examined, either.

Furthermore, in a zoom lens disclosed in Japanese Patent Application Laid-Open Nos. 57-4018, 58-137812, 58-137814, 58-144808, 58-149014, 58-150925, and the like, each of which utilizes only a focus cam, the problems of the storage capacity, calculation error, and the like have not been examined, either.

On the other hand, as in Japanese Patent Application Laid-Open Nos. 63-163808, 1-154014, and the like assigned to the same assignee as the present invention, in a zoom lens disclosed in Japanese Patent Application Laid-Open Nos. 64-35515, 64-35516, 4-140704, and the like, each of which commonly uses a single cam as both a focus cam and a zoom cam, the above-mentioned problems of the storage capacity, calculation error, and the like have not been examined, either. In addition, the zoom lens disclosed in these references has a basic structure different from that of the present invention since it does not require any zoom compensation cam, and does not take a so-called flexible manual focusing operation into account, which has been examined in Japanese Patent Application Laid-Open Nos. 4-293008, 5-142475, and the like.

A zoom lens disclosed in Japanese Patent Application Laid-Open Nos. 2-256011 and 3-101707 which have been assigned to the same assignee as the present invention, and No. 7-120662 which discloses a technical content similar to those disclosed in the above Japanese Patent Application Laid-Open Nos. 2-256011 and 3-101707, has a basic structure different from that of the present invention since it realizes zooming by a relative movement, in the direction of rotation of a lens barrel, between a focus cam and a zoom cam, and focusing by a relative movement in the direction of the optical axis, and does not examine an auto-focusing operation at all.

Similarly, in Japanese Patent Application Laid-Open No. 7-5362, a zoom lens disclosed therein has a basic structure different from that of the present invention since the amount of movement for focusing is to be defined by synthesizing two kinds of cams without using a focus cam directly, and the above-mentioned problems concerning the storage capacity, calculation error, and the like have not been examined.

Furthermore, Japanese Patent Application Laid-Open Nos. 61-77027, 1-232313, and the like discloses a lens system having a focus cam so as to realize an accurate auto-focusing operation with a small calculation error. However, these references relate to a single-focus lens having no zooming function, and cannot be applied to a focus cam required to achieve a so-called manual focusing operation in a zoom lens in which the amount of movement in the direction of the optical axis for focusing changes depending on the zooming state.

The principle of the auto-focus operation will be briefly described below.

An auto-focusing system disclosed in Japanese Patent Application Laid-Open Nos. 62-78519, 62-170924, 1-131507, 1-131508, 1-131509, 3-228006, and the like, comprises focus detection means, calculation means for calculating the lens driving amount for focusing, and storage means for storing specific constants used in calculations. In this system, the focus detection means detects the defocus amount ΔBf between the imaging position of an actual object by the photographing optical system and a predetermined imaging point position, and the calculation means for calculating the lens driving amount for focusing calculates the lens driving amount Δx for focusing on the basis of the detected defocus amount ΔBf of the photographing optical system, thus achieving an auto-focusing operation.

If the relationship between the lens driving amount Δx for focusing and the defocus amount ΔBf is expressed using a conversion coefficient K associated with focusing as follows:

    Δx=ΔBf/K

then, the lens driving amount Δx can be calculated by setting the conversion coefficient K.

However, as described in Japanese Patent Application Laid-Open No. 62-170924, the conversion coefficient K changes in correspondence not only with the focal length but also with the object position and lens arrangement.

Therefore, as described in Japanese Patent Application Laid-Open Nos. 62-78519, 62-170924, and the like, using the conversion coefficient γ defined as the ratio (sensitivity) of the amount of infinitesimal movement of the imaging plane with respect to the amount of infinitesimal movement of the focusing lens unit in the vicinity of a predetermined in-focus point, and the correction coefficient ε for correcting the conversion coefficient in accordance with the defocus amount ΔBf, the conversion coefficient K is calculated by the following formulas:

    K=γ+ε·f(ΔBf)

    K=γ+ε·ΔBf.sup.2

in Japanese Patent Application Laid-Open No. 62-78519

    K=γ(1+ε·ΔBf)

in Japanese Patent Application Laid-Open No. 62-170924

and thereafter, the lens driving amount Δx is calculated based on the conversion coefficient K.

(Of course, the lens driving amount Δx for focusing may be directly calculated from the defocus amount ΔBf using the conversion coefficient γ and the correction coefficient ε.)

Furthermore, in a photographing system having a zooming optical system, since the values of the conversion coefficient γ and the correction coefficient ε change depending on the lens arrangement, a plurality of pairs of data of the conversion coefficient γ and the correction coefficient ε are stored in the storage means in units of a plurality of divided zoom ranges and focus ranges, as described in Japanese Patent Application Laid-Open No. 3-228006.

In other words, in the photographing system having the zooming optical system, the focus detection means detects the defocus amount ΔBf caused by the zooming optical system, and values of the conversion coefficient γ and the correction coefficient ε corresponding to the zoom and focus positions respectively detected by zoom and focus position detection means are read out from the storage means. The calculation means for calculating the lens driving amount for focusing calculates the lens driving amount Δx for focusing using the defocus amount ΔBf, the conversion coefficient γ, and the correction coefficient ε, and driving means drives a lens by the calculated lens driving amount Δx for focusing, thus achieving a focusing operation.

However, in a normal focusing mechanism using a helicoid mechanism or a cam mechanism, the lens driving amount for focusing must be described not as a lens driving amount Δx in the direction of the optical axis but as a lens driving amount Δa in the direction of rotation.

Therefore, when the relationship between the lens driving amount Δx and the defocus amount ΔBf in the direction of the optical axis is converted into the relationship between the lens driving amount Δa and the defocus amount ΔBf in the direction of rotation using a conversion coefficient K_(a) associated with the direction of rotation, we have:

    Δa=ΔBf/K.sub.a

If conversion coefficient K associated with the direction of the optical axis is newly defined as K_(x), the conversion coefficient K_(a) associated with the direction of rotation is expressed using a conversion coefficient Φ between the lens driving amount Δx in the direction of the optical axis and the lens driving amount Δa in the direction of rotation as follows:

    K.sub.a =K.sub.x ·Φ

Thus, the formula in Japanese Patent Application Laid-Open No. 62-170924 is modified to a formula associated with the conversion coefficient K_(a) in the direction of rotation as follows:

    K.sub.a =Φγ(1 +ε·ΔBf)

If Δx and Aa have a linear relationship therebetween like in a helicoid mechanism, Φ becomes a constant. However, when a cam mechanism is used, the conversion coefficient Φ changes depending on the cam shape. The conversion coefficient Φ can be replaced by a slope (dx/da) defined by the cam shape as follows:

    K.sub.a =γ·(dx/da)(1 +ε·ΔBf)

The conversion coefficient γ and the correction coefficient ε in an inner focusing type zoom lens disclosed in Japanese Patent Application Laid-Open Nos. 4-293008, 5-142475, and the like will be examined below.

When a zoom lens system is constituted by n lens units, and its k-th lens unit is used as the focusing lens unit, if the ratio of the amount dBf of infinitesimal movement of the imaging plane to the amount dx of infinitesimal movement, in the direction of the optical axis, of the focusing lens unit, i.e., the conversion coefficient γ (dBf/dx: the sensitivity associated with movement in the direction of the optical axis) is defined as a new conversion coefficient γ_(x) associated with the amount x of movement in the direction of the optical axis, the conversion coefficient γ_(x) can be expressed using the imaging magnifications β of the respective lens units as follows:

    γ.sub.x =(1-β.sub.k.sup.2)β.sub.k+1.sup.2 β.sub.k+2.sup.2 . . . β.sub.n.sup.2

Therefore, the rate of change, from the infinity in-focus value (γ_(xO)) to the closest in-focus value (γ_(xR)), of the conversion coefficient γ_(x) associated with the amount x of movement in the direction of the optical axis can be expressed using the imaging magnifications β_(ok) and β_(Rk) of the focusing lens unit at the infinity and closest in-focus points as follows:

    γ.sub.xR /γ.sub.xO =(1-β.sub.Rk.sup.2)/(1-β.sub.0k.sup.2)

Furthermore, if the ratio of the amount dBf of infinitesimal movement of the imaging plane to the angle da of infinitesimal rotation of the focusing lens unit (dBf/da: the sensitivity associated with movement in the direction of rotation) is defined as a new conversion coefficient γ_(a) associated with the angle a of rotation of a rotatable lens barrel, the conversion coefficient γ_(a) associated with the angle a of rotation of the rotatable lens barrel can be expressed by:

    γ.sub.a =γ.sub.x ·(dx/da)

where dx/da is the slope of the focus cam.

Therefore, the rate of change, from the infinity in-focus value (γ_(aO)) to the closest in-focus value (γ_(aR)), of the conversion coefficient γ_(a) associated with the angle a of rotation of the rotatable lens barrel can be expressed using slopes (dx/da)_(O) and (dx/da)_(R) at the infinity and closest corresponding positions on the focus cam as follows:

    γ.sub.aR /γ.sub.aO =(γ.sub.xR /γ.sub.xO)·((dx/da).sub.R /(dx/da).sub.O)

The rate of change of the conversion coefficient γ_(x) with respect to the amount x of movement in the direction of the optical axis and the rate of change of the conversion coefficient γ_(a) with respect to the angle a of rotation of the rotatable lens barrel will be examined below in association with an embodiment of Japanese Patent Application Laid-Open No. 5-142475. Note that the amount of rotation for zooming from the wide-angle end to the telephoto end and the amount of rotation for focusing are respectively re-set to be 10.0 for the purpose of a comparison with an embodiment of the present invention.

Table 1 below summarizes various paraxial data of an optical system and data for defining the shape of the focus cam corresponding to the embodiment of Japanese Patent Application Laid-Open No. 5-142475.

The upper table in Table 1 summarizes the focal length data and principal point interval data of the respective lens units of the optical system corresponding to the embodiment of Japanese Patent Application Laid-Open No. 5-142475. In this table, F1, F2, F3, and F4 are respectively the focal lengths of first, second, third and fourth lens units, and D1, D2, D3, and D4 are respectively the principal point interval between the first and second lens units, the principal point interval between the second and third lens units, the principal point interval between the third and fourth lens units, and the principal point interval between the fourth lens unit and a predetermined imaging plane in six zooming states (focal lengths F=36.0 (1-POS), 50.0 (2-POS), 60.0 (3-POS), 70.0 (4-POS), 85.0 (5-POS), and 103.0 (6-POS) mm).

The middle table in Table 1 summarizes spline sample point data when the shape of the focus cam in the second lens unit which is used for focusing is expressed by a spline function associated with the angle a of rotation of the rotatable lens barrel and the amount x of movement in the direction of the optical axis (complying with "Numerical Analysis and FORTRAN", MARUZEN, "Spline Function and Its Applications", Kyoiku Shuppan, and the like). In this middle table, (1), (2), (3), and (4) correspond to the first, second, third, and fourth lens units, respectively.

Furthermore, the lower table in Table 1 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=36.0, 50.0, 60.0, 70.0, 85.0, and 103.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.85 m) using the focus cam. Since both the amount of rotation for zooming from the wide-angle end (F=36.0) to t5he telephoto end (F=103.0) and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=0.85 m) are 10.0, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming is 1.0.

                                      TABLE 1                                      __________________________________________________________________________     Data of Embodiment of Japanese Patent Application Laid-Open No. 5-142475       (Rotation Amount Ratio: a.sub.F /a.sub.Z = 1.0)                                __________________________________________________________________________     Focal lengths and Principal Point Intervals of Lens Units of Embodiment        of Japanese Patent Application Laid-Open No. 5-142475                                      1-POS                                                                              2-POS                                                                               3-POS                                                                              4-POS                                                                               5-POS                                                                              6-POS                                        __________________________________________________________________________             F .sup.                                                                            36.0000                                                                            50.0000                                                                             60.0000                                                                            70.0000                                                                             85.0000                                                                            103.0000                                     F1 71.3528                                                                             D1  10.0000                                                                            16.9506                                                                             20.8432                                                                            24.0040                                                                             27.6859                                                                            31.0684                                      F2 -16.8076                                                                            D2  18.0119                                                                            13.8825                                                                             11.8221                                                                            10.1086                                                                              7.9077                                                                             5.6236                                      F3 37.3219                                                                             D3  13.2200                                                                            12.3744                                                                             11.9702                                                                            11.6986                                                                             11.3811                                                                            11.3103                                      F4 61.7098                                                                             D4  53.2211                                                                            59.4228                                                                             62.5744                                                                            65.1172                                                                             68.2854                                                                            71.2371                                      __________________________________________________________________________     Focus Cam Shape (Spline Interpolation) Corresponding to Embodiment             of Japanese Patent Application Laid-Open No. 5-142475                            ANGLE     (1)                                                                               (2)        (3)                                                                               (4)                                               __________________________________________________________________________      1                                                                                .0000    .0000                                                                              .0000     .0000                                                                             .0000                                              2                                                                                3.3787   .0000                                                                              .1701     .0000                                                                             .0000                                              3                                                                                4.8214   .0000                                                                              .2847     .0000                                                                             .0000                                              4                                                                                6.2247   .0000                                                                              .4295     .0000                                                                             .0000                                              5                                                                                7.3653   .0000                                                                              .5760     .0000                                                                             .0000                                              6                                                                                9.1918   .0000                                                                              .8749     .0000                                                                             .0000                                              7                                                                               10.0000   .0000                                                                             1.0365     .0000                                                                             .0000                                              8                                                                               13.3787   .0000                                                                             1.9870     .0000                                                                             .0000                                              9                                                                               14.8214   .0000                                                                             2.5248     .0000                                                                             .0000                                             10                                                                               16.2247   .0000                                                                             3.1268     .0000                                                                             .0000                                             11                                                                               17.3653   .0000                                                                             3.6722     .0000                                                                             .0000                                             12                                                                               19.1918   .0000                                                                             4.6460     .0000                                                                             .0000                                             13                                                                               20.0000   .0000                                                                             5.1165     .0000                                                                             .0000                                             __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation for Focusing of          Embodiment of Japanese Patent Application No. 5-142475                         (Rotation Amount Ratio: a.sub.F /a.sub.Z = 1.0)                                      Infinity            Amount of                                                  Corresponding                                                                               Photographing                                                                         Rotation                                             Focal Length                                                                         Position     Distance                                                                              for Focusing                                         __________________________________________________________________________      36.0 mm                                                                              .0000       5.00 m  3.379                                                50.0 mm                                                                              2.1079      3.00 m  4.821                                                60.0 mm                                                                              3.5742      2.00 m  6.225                                                70.0 mm                                                                              5.0485      1.50 m  7.365                                                85.0 mm                                                                              7.2321      1.00 m  9.192                                               103.0 mm                                                                             10.0000      0.85 m 10.000                                               __________________________________________________________________________     Conditional Corresponding Value (1)                                                             1.05 (wide-angle end)                                                                     1.59 (telephoto end)                               Conditional Corresponding Value (2)                                                             3.94                                                          Conditional Corresponding Value (3)                                                             1.00                                                          Conditional Corresponding Value (4)                                                             5.43 (wide-angle end)                                                                     4.36 (telephoto end)                               Conditional Corresponding Value (5)                                                             2.75 (wide-angle end)                                                                     3.80 (telephoto end)                               Conditional Corresponding Value (6)                                                             0.44 (wide-angle end)                                                                     0.43 (telephoto end)                               __________________________________________________________________________

Table 2 below summarizes the numerical value data of the cams of the focusing lens unit in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 1. In this table, (ANGLE) is the angle of rotation of the rotatable lens barrel, (2) is the amount (mm) of movement, in the direction of the optical axis, of the second lens unit, and (F) is the focal length (mm) of the entire system in an infinity in-focus state corresponding to the amount (ANGLE) of rotation.

                  TABLE 2                                                          ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit in Embodiment of                Japanese Patent Application Laid-Open No. 5-142475                                                   Zoom Compensation Cam                                    Focus Cam Numerical Value Data                                                                       Cam Numerical Value Data                                 ANGLE  (2)     F          ANGLE (2)     F                                      ______________________________________                                         .0000  .0000   36.0000    .0000 .0000   36.0000                                .5000  .0208   39.1417    .5000 .0208   39.1417                                1.0000 .0423   42.4381    1.0000                                                                               .5684   42.4381                                1.5000 .0649   45.8280    1.5000                                                                               .8335   45.8280                                2.0000 .0892   49.2589    2.0000                                                                               1.0810  49.2589                                2.5000 .1158   52.6890    2.5000                                                                               1.3090  52.6890                                3.0000 .1454   56.1033    3.0000                                                                               1.5167  56.1033                                3.5000 .1785   59.4978    3.5000                                                                               1.7038  59.4978                                4.0000 .2154   62.8763    4.0000                                                                               1.8710  62.8763                                4.5000 .2563   66.2597    4.5000                                                                               2.0204  66.2597                                5.0000 .3012   69.6675    5.0000                                                                               2.1534  69.6675                                5.5000 .3503   73.1066    5.5000                                                                               2.2712  73.1066                                6.0000 .4039   76.5591    6.0000                                                                               2.3738  76.5591                                6.5000 .4623   80.0055    6.5000                                                                               2.4616  80.0055                                7.0000 .5260   83.4263    7.0000                                                                               2.5347  83.4263                                7.5000 .5953   86.8023    7.5000                                                                               2.5931  86.8023                                8.0000 .6705   90.1274    8.0000                                                                               2.6372  90.1274                                8.5000 .7518   93.4109    8.5000                                                                               2.6680  93.4109                                9.0000 .8395   96.6628    9.0000                                                                               2.6860  96.6628                                9.5000 .9340   99.8856    9.5000                                                                               2.6916  99.8856                                10.0000                                                                               1.0365  103.0000   10.0000                                                                              2.6814  103.0000                               10.5000                                                                               1.1489  .0000                                                           11.0000                                                                               1.2714  .0000                                                           11.5000                                                                               1.4038  .0000                                                           12.0000                                                                               1.5460  .0000                                                           12.5000                                                                               1.6977  .0000                                                           13.0000                                                                               1.8588  .0000                                                           13.5000                                                                               2.0292  .0000                                                           14.0000                                                                               2.2088  .0000                                                           14.5000                                                                               2.3980  .0000                                                           15.0000                                                                               2.5971  .0000                                                           15.5000                                                                               2.8062  .0000                                                           16.0000                                                                               3.0252  .0000                                                           16.5000                                                                               3.2540  .0000                                                           17.0000                                                                               3.4924  .0000                                                           17.5000                                                                               3.7397  .0000                                                           18.0000                                                                               3.9959  .0000                                                           18.5000                                                                               4.2617  .0000                                                           19.0000                                                                               4.5374  .0000                                                           19.5000                                                                               4.8236  .0000                                                           20.0000                                                                               5.1165  .0000                                                           ______________________________________                                    

The left table in Table 2 summarizes the numerical value data of the focus cam in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, and the right table in Table 2 summarizes the numerical value data of the zoom compensation cam of the embodiment. A value obtained by synthesizing the amount (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in a range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE =10.0) agrees with the movement locus of the second lens unit calculated using the paraxial data in the upper table in Table 1.

Tables 3, 4, and 5 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(K) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=36.0), the middle position (F=50.0), and the telephoto end (F=103.0), respectively. In these tables, (R) on the left side is the photographing distance (m), (ANG) is the amount of rotation on the focus cam upon focusing to the respective photographing distances, and 1), 2), 3), and 4) on the right side respectively represent the first, second, third, and fourth lens units. Also, in these tables, the first table summarizes the amount DX (mm) of movement for focusing in the direction of the optical axis upon focusing to the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.85 m) (note that movement toward the object side is positive). The second table summarizes the imaging magnifications β_(K) of the respective lens units in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.85 m). The third table summarizes the conversion coefficient γ_(x) associated with the direction of the optical axis of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.85 m). Furthermore, the fourth table summarizes the slope (dx/da) of the focus cam at the positions, on the focus cam, corresponding to an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.85 m), and the fifth table summarizes the conversion coefficient γ_(a) associated with the direction of rotation of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.85 m).

                  TABLE 3                                                          ______________________________________                                         Amount DX (mm) of Movement for Focusing in Direction of                        Optical Axis at Wide-angle End (36.0 mm) in                                    Japanese Patent Application Laid-Open No. 5-142475                             R   .000 ANG  .000 1)  .000 2)                                                                               .000 3)                                                                               .000 4)                                                                               .000                               R   10.000 ANG                                                                               1.912 1) .000 2)                                                                               .085 3)                                                                               .000 4)                                                                               .000                               R   5.000 ANG 3.379 1) .000 2)                                                                               .170 3)                                                                               .000 4)                                                                               .000                               R   3.000 ANG 4.821 1) .000 2)                                                                               .285 3)                                                                               .000 4)                                                                               .000                               R   2.000 ANG 6.225 1) .000 2)                                                                               .429 3)                                                                               .000 4)                                                                               .000                               R   1.500 ANG 7.365 1) .000 2)                                                                               .576 3)                                                                               .000 4)                                                                               .000                               R   1.000 ANG 9.192 1) .000 2)                                                                               .875 3)                                                                               .000 4)                                                                               .000                               R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               1.037 3)                                                                              .000 4)                                                                               .000                               Imaging Magnification β.sub.K of Lens Units at Wide-angle End (36.0       mm)                                                                            in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               -.377 3)                                                                              -9.721 4)                                                                             .138                               R   10.000 ANG                                                                               1.912 1) -.007 2)                                                                              -.372 3)                                                                              -9.721 4)                                                                             .138                               R   5.000 ANG 3.379 1) -.015 2)                                                                              -.367 3)                                                                              -9.721 4)                                                                             .138                               R   3.000 ANG 4.821 1) -.025 2)                                                                              -.360 3)                                                                              -9.721 4)                                                                             .138                               R   2.000 ANG 6.225 1) -.039 2)                                                                              -.352 3)                                                                              -9.721 4)                                                                             .138                               R   1.500 ANG 7.365 1) -.054 2)                                                                              -.343 3)                                                                              -9.721 4)                                                                             .138                               R   1.000 ANG 9.192 1) -.088 2)                                                                              -.325 3)                                                                              -9.721 4)                                                                             .138                               R   .850 ANG  10.000 1)                                                                               -.107 2)                                                                              -.316 3)                                                                              -9.721 4)                                                                             .138                               Conversion Coefficient γ.sub.x Associated With                           Direction of Optical Axis at Wide-angle End (36.0 mm)                          in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               1.533 3)                                                                              .000 4)                                                                               .000                               R   10.000 ANG                                                                               1.912 1) .000 2)                                                                               1.540 3)                                                                              .000 4)                                                                               .000                               R   5.000 ANG 3.379 1) .000 2)                                                                               1.547 3)                                                                              .000 4)                                                                               .000                               R   3.000 ANG 4.821 1) .000 2)                                                                               1.556 3)                                                                              .000 4)                                                                               .000                               R   2.000 ANG 6.225 1) .000 2)                                                                               1.567 3)                                                                              .000 4)                                                                               .000                               R   1.500 ANG 7.365 1) .000 2)                                                                               1.578 3)                                                                              .000 4)                                                                               .000                               R   1.000 ANG 9.192 1) .000 2)                                                                               1.599 3)                                                                              .000 4)                                                                               .000                               R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               1.610 3)                                                                              .000 4)                                                                               .000                               Slope (dx/da of Focus Cam at Wide-angle End (36.0 mm)                          in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               .041 3)                                                                               .000 4)                                                                               .000                               R   10.000 ANG                                                                               1.912 1) .000 2)                                                                               .050 3)                                                                               .000 4)                                                                               .000                               R   5.000 ANG 3.379 1) .000 2)                                                                               .068 3)                                                                               .000 4)                                                                               .000                               R   3.000 ANG 4.821 1) .000 2)                                                                               .091 3)                                                                               .000 4)                                                                               .000                               R   2.000 ANG 6.225 1) .000 2)                                                                               .116 3)                                                                               .000 4)                                                                               .000                               R   1.500 ANG 7.365 1) .000 2)                                                                               .141 3)                                                                               .000 4)                                                                               .000                               R   1.000 ANG 9.192 1) .000 2)                                                                               .187 3)                                                                               .000 4)                                                                               .000                               R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               .215 3)                                                                               .000 4)                                                                               .000                               Conversion Coefficient γ.sub.a Associated With                           Direction of Rotation at Wide-angle End (36.0 mm)                              in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               .064 3)                                                                               000 4) .000                               R   10.000 ANG                                                                               1.912 1) .000 2)                                                                               .077 3)                                                                               .000 4)                                                                               .000                               R   5.000 ANG 3.379 1) .000 2)                                                                               .105 3)                                                                               .000 4)                                                                               .000                               R   3.000 ANG 4.821 1) .000 2)                                                                               .141 3)                                                                               .000 4)                                                                               .000                               R   2.000 ANG 6.225 1) .000 2)                                                                               .182 3)                                                                               .000 4)                                                                               .000                               R   1.500 ANG 7.365 1) .000 2)                                                                               .223 3)                                                                               .000 4)                                                                               .000                               R   1.000 ANG 9.192 1) .000 2)                                                                               .299 3)                                                                               .000 4)                                                                               .000                               R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               .346 3)                                                                               .000 4)                                                                               .000                               ______________________________________                                          Condition Corresponding Values: γ.sub.xK /γ.sub.xO = 1.05          γ.sub.aK /γ.sub.aO = 5.43                                    

                  TABLE 4                                                          ______________________________________                                         Amount DX (mm) of Movement for Focusing in Direction of                        Optical Axis at Middle Position (50.0 mm)                                      in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               .000 3)                                                                               .000 4) .000                              R   10.000 ANG                                                                               1.972 1) .000 2)                                                                               .127 3)                                                                               .000 4) .000                              R   5.000 ANG 3.373 1) .000 2)                                                                               .254 3)                                                                               .000 4) .000                              R   3.000 ANG 4.821 1) .000 2)                                                                               .422 3)                                                                               .000 4) .000                              R   2.000 ANG 6.241 1) .000 2)                                                                               .632 3)                                                                               .000 4) .000                              R   1.500 ANG 7.403 1) .000 2)                                                                               .841 3)                                                                               .000 4) .000                              R   1.000 ANG 9.213 1) .000 2)                                                                               1.261 3)                                                                              .000 4) .000                              R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               1.483 3)                                                                              .000 4) .000                              Imaging Magnification β.sub.K of Lens Units at Middle Position (50.0      mm)                                                                            in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               -.447 3)                                                                              -42.292 4) .037                           R   10.000 ANG                                                                               1.972 1) -.007 2)                                                                              -.440 3)                                                                              -42.292 4) .037                           R   5.000 ANG 3.373 1) -.015 2)                                                                              -.432 3)                                                                              -42.292 4) .037                           R   3.000 ANG 4.821 1) -.025 2)                                                                              -.422 3)                                                                              -42.292 4) .037                           R   2.000 ANG 6.241 1) -.040 2)                                                                              -.409 3)                                                                              -42.292 4) .037                           R   1.500 ANG 7.403 1) -.055 2)                                                                              -.397 3)                                                                              -42.292 4) .037                           R   1.000 ANG 9.213 1) -.089 2)                                                                              -.372 3)                                                                              -42.292 4) .037                           R   .850 ANG  10.000 1)                                                                               -.109 2)                                                                              -.359 3)                                                                              -42.292 4) .037                           Conversion Coefficient γ.sub.x Associated With                           Direction of Optical Axis at Middle Position (50.0 mm)                         in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               1.966 3)                                                                              .000 4) .000                              R   10.000 ANG                                                                               1.972 1) .000 2)                                                                               1.982 3)                                                                              .000 4) .000                              R   5.000 ANG 3.373 1) .000 2)                                                                               1.998 3)                                                                              .000 4) .000                              R   3.000 ANG 4.821 1) .000 2)                                                                               2.019 3)                                                                              .000 4) .000                              R   2.000 ANG 6.241 1) .000 2)                                                                               2.045 3)                                                                              .000 4) .000                              R   1.500 ANG 7.403 1) .000 2)                                                                               2.069 3)                                                                              .000 4) .000                              R   1.000 ANG 9.213 1) .000 2)                                                                               2.117 3)                                                                              .000 4) .000                              R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               2.140 3)                                                                              .000 4) .000                              Slope dx/da of Focus Cam at Middle Position (50.0 mm)                          in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               .052 3)                                                                               .000 4) .000                              R   10.000 ANG                                                                               1.972 1) .000 2)                                                                               .079 3)                                                                               .000 4) .000                              R   5.000 ANG 3.373 1) .000 2)                                                                               .102 3)                                                                               .000 4) .000                              R   3.000 ANG 4.821 1) .000 2)                                                                               .131 3)                                                                               .000 4) .000                              R   2.000 ANG 6.241 1) .000 2)                                                                               .165 3)                                                                               .000 4) .000                              R   1.500 ANG 7.403 1) .000 2)                                                                               .197 3)                                                                               .000 4) .000                              R   1.000 ANG 9.213 1) .000 2)                                                                               .268 3)                                                                               .000 4) .000                              R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               .298 3)                                                                               .000 4) .000                              Conversion Coefficient γ.sub.a Associated With                           Direction of Rotation at Middle Position (50.0 mm)                             in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               .102 3)                                                                               .000 4) .000                              R   10.000 ANG                                                                               1.972 1) .000 2)                                                                               .157 3)                                                                               .000 4) .000                              R   5.000 ANG 3.373 1) .000 2)                                                                               .204 3)                                                                               .000 4) .000                              R   3.000 ANG 4.821 1) .000 2)                                                                               .265 3)                                                                               .000 4) .000                              R   2.000 ANG 6.241 1) .000 2)                                                                               .338 3)                                                                               .000. 4) .000                             R   1.500 ANG 7.403 1) .000 2)                                                                               .407 3)                                                                               .000 4) .000                              R   1.000 ANG 9.213 1) .000 2)                                                                               .566 3)                                                                               .000 4) .000                              R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               .638 3)                                                                               .000 4) .000                              ______________________________________                                          Condition Corresponding Values: γ.sub.xK /γ.sub.xO = 1.09,         γ.sub.aK /γ.sub.aO = 6.26                                    

                  TABLE 5                                                          ______________________________________                                         Amount DX (mm) of Movement for Focusing in Direction of                        Optical Axis at Telephoto End (103.00 mm)                                      in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               .000 3)                                                                               .000 4)                                                                               .000                               R   10.000 ANG                                                                               1.975 1) .000 2)                                                                               .502 3)                                                                               .000 4)                                                                               .000                               R   5.000 ANG 3.379 1) .000 2)                                                                               .951 3)                                                                               .000 4)                                                                               .000                               R   3.000 ANG 4.821 1) .000 2)                                                                               1.488 3)                                                                              .000 4)                                                                               .000                               R   2.000 ANG 6.225 1) .000 2)                                                                               2.090 3)                                                                              .000 4)                                                                               .000                               R   1.500 ANG 7.365 1) .000 2)                                                                               2.636 3)                                                                              .000 4)                                                                               .000                               R   1.000 ANG 9.192 1) .000 2)                                                                               3.609 3)                                                                              .000 4)                                                                               .000                               R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               4.080 3)                                                                              .000 4)                                                                               .000                               Imaging Magnification β.sub.K of Lens Units at Telephoto End (103.0       mm)                                                                            in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               -.716 3)                                                                              13.060 4)                                                                             -.154                              R   10.000 ANG                                                                               1.975 1) -.007 2)                                                                              -.686 3)                                                                              13.060 4)                                                                             -.154                              R   5.000 ANG 3.379 1) -.015 2)                                                                              -.659 3)                                                                              13.060 4)                                                                             -.154                              R   3.000 ANG 4.821 1) -.026 2)                                                                              -.627 3)                                                                              13.060 4)                                                                             -.154                              R   2.000 ANG 6.225 1) -.040 2)                                                                              -.592 3)                                                                              13.060 4)                                                                             -.154                              R   1.500 ANG 7.365 1) -.055 2)                                                                              -.559 3)                                                                              13.060 4)                                                                             -.154                              R   1.000 ANG 9.192 1) -.090 2)                                                                              -.501 3)                                                                              13.060 4)                                                                             -.154                              R   .850 ANG  10.000 1)                                                                               -.112 2)                                                                              -.473 3)                                                                              13.060 4)                                                                             -.154                              Conversion Coefficient γ.sub.x Associated With                           Direction of Optical Axis at Telephoto End (103.0 mm)                          in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               1.982 3)                                                                              .000 4)                                                                               .000                               R   10.000 ANG                                                                               1.975 1) .000 2)                                                                               2.152 3)                                                                              .000 4)                                                                               .000                               R   5.000 ANG 3.379 1) .000 2)                                                                               2.298 3)                                                                              .000 4)                                                                               .000                               R   3.000 ANG 4.821 1) .000 2)                                                                               2.465 3)                                                                              .000 4)                                                                               .000                               R   2.000 ANG 6.225 1) .000 2)                                                                               2.643 3)                                                                              .000 4)                                                                               .000                               R   1.500 ANG 7.365 1) .000 2)                                                                               2.795 3)                                                                              .000 4)                                                                               .000                               R   1.000 ANG 9.192 1) .000 2)                                                                               3.044 3)                                                                              .000 4)                                                                               .000                               R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               3.155 3)                                                                              .000 4)                                                                               .000                               Slope dx/da of Focus Cam at Telephoto End (103.0 mm)                           in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               .215 3)                                                                               .000 4)                                                                               .000                               R   10.000 ANG                                                                               1.975 1) .000 2)                                                                               .293 3)                                                                               .000 4)                                                                               .000                               R   5.000 ANG 3.379 1) .000 2)                                                                               .345 3)                                                                               .000 4)                                                                               .000                               R   3.000 ANG 4.821 1) .000 2)                                                                               .401 3)                                                                               .000 4)                                                                               .000                               R   2.000 ANG 6.225 1) .000 2)                                                                               .457 3)                                                                               .000 4)                                                                               .000                               R   1.500 ANG 7.365 1) .000 2)                                                                               .499 3)                                                                               .000 4)                                                                               .000                               R   1.000 ANG 9.192 1) .000 2)                                                                               .570 3)                                                                               .000 4)                                                                               .000                               R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               .588 3)                                                                               .000 4)                                                                               .000                               Conversion Coefficient γ.sub.a Associated With                           Direction of Rotation at Telephoto End (103.0 mm)                              in Japanese Patent Application Laid-Open No. 5-142475                          R   .000 ANG  .000 1)  .000 2)                                                                               .425 3)                                                                               .000 4)                                                                               .000                               R   10.000 ANG                                                                               1.975 1) .000 2)                                                                               .630 3)                                                                               .000 4)                                                                               .000                               R   5.000 ANG 3.379 1) .000 2)                                                                               .794 3)                                                                               .000 4)                                                                               .000                               R   3.000 ANG 4.821 1) .000 2)                                                                               .989 3)                                                                               .000 4)                                                                               .000                               R   2.000 ANG 6.225 1) .000 2)                                                                               1.207 3)                                                                              .000 4)                                                                               .000                               R   1.500 ANG 7.365 1) .000 2)                                                                               1.394 3)                                                                              .000 4)                                                                               .000                               R   1.000 ANG 9.192 1) .000 2)                                                                               1.736 3)                                                                              .000 4)                                                                               .000                               R   .850 ANG  10.000 1)                                                                               .000 2)                                                                               1.855 3)                                                                              .000 4)                                                                               .000                               ______________________________________                                          Condition Corresponding Values: γ.sub.xK /γ.sub.xO = 1.59          γ.sub.aK /γ.sub.aO = 4.36                                    

As can be seen from Tables 3, 4, and 5, the conversion coefficient γ_(x) associated with the direction of the optical axis and the slope (dx/da) of the focus cam at the respective focal lengths increase as the photographing distance becomes closer to the closest distance. Therefore, as can be seen from these tables, the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of γ_(x) and (dx/da), further increases.

More specifically, in a zoom lens in which the conversion coefficient γ_(x) associated with the amount x of movement, in the direction of the optical axis, of the focusing lens unit in a closest in-focus state is larger than that in an infinity in-focus state, i.e., which satisfies:

    1.0<γ.sub.xR /γ.sub.xO

when the focus cam which satisfies the following inequality, i.e., the focus cam has a shape having a larger slope (dx/da) at the closest corresponding position than that at the infinity corresponding position:

    1.0<< (dx/da).sub.R /(dx/da).sub.O

the following inequality is satisfied:

    1.0<γ.sub.xR /γ.sub.xO <<γ.sub.aR /γ.sub.aO

The rate of change, from the infinity in-focus value (γ_(aO)) to the closest in-focus value (γ_(aR)), of the conversion coefficient γ_(a) associated with the angle a of rotation of the rotatable lens barrel undesirably becomes larger than the rate of change, from the infinity in-focus value (γ_(xO)) to the closest in-focus value (γ_(xR)), of the conversion coefficient γ_(x) associated with the amount x of movement in the direction of the optical axis.

From Tables 3, 4, and 5 above, the rate of change of γ_(a) is ×5.43 at the wide-angle end (F=36.0), ×6.26 at the middle position (F=50.0), and ×4.36 at the telephoto-end (F=103.0).

As described above, when the conversion coefficient γ changes in correspondence with the lens arrangement (e.g., focusing), as described in Japanese Patent Application Laid-Open No. 3-228006, a plurality of pairs of data of the conversion coefficient γ and the correction coefficient ε must be stored in the storage means in units of a plurality of divided focus ranges. Therefore, when the rate of change of γ_(a) is large (γ_(aR) /γ_(aO) >>1.0), the number of divisions increases, and the storage capacity inevitably becomes large, resulting in an increase in cost. For example, when a change in γ_(a) in a single focus range is divided under the condition defined by the following inequality:

    γ.sub.max /γ.sub.min <1.2

the number N of divisions is expressed by inequality (a) below:

    N>log(γ.sub.MAX /γ.sub.MIN)/log(1.2)           (a)

Therefore, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end have large values as follows:

    N.sub.W >9.3 N.sub.M >10.1 N.sub.T >8.1

The formula K=γ (1+ε·ΔBf) presented by Japanese Patent Application Laid-Open No. 62-170924 is rewritten to the conversion coefficient K_(a) associated with the angle a of rotation of the rotatable lens barrel:

    K.sub.a =γ.sub.a (1+ε·ΔBf)

Then, the following formula is defined by using a correction coefficient μ (ε=-1/μ):

    K.sub.a =γ.sub.a (1-ΔBf/μ)

Tables 6, 7, and 8 below summarize the calculation results of the values of the conversion coefficient K_(a) and the correction coefficient μ according to the embodiment of Japanese Patent Application Laid-Open No. 5-142475 at the wide-angle end (F=36.0), middle position (F=50.0), and telephoto end (F=103.0) using the above formula.

In these tables, (R) is the object distance (m), (ANG) is the amount of rotation for focusing from the infinity corresponding position on the focus cam, (r) is the conversion coefficient γ_(a) in the direction of rotation, (rs) is the conversion coefficient K_(a), (bf) is the defocus amount (mm), and (l) is the correction coefficient μ. Each table has a matrix structure, and eight rows in the vertical direction indicated by (POS) represent the object positions (R=10.0, 5.0, 3.0, 2.0, 1.5, 1.0, and 0.85 mm), and four pairs (R, ANGLE) in the horizontal direction represent the lens arrangements of the focusing lens unit.

More specifically, the position of the focusing lens in the first pair in the upper two tables in each of Tables 6, 7, and 8, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Therefore, the third column (r) in the first table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on an infinity object, and the fourth column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column. Furthermore, the third column (bf) in the second table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the infinity corresponding position, and the object is located at an object distance in the second column, and the fourth column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column.

Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 6, 7, and 8, i.e., in the ninth and 10th columns is (R, ANGLE)=(0.85, 10.0), and it indicates that this position corresponds to the closest in-focus (R=0.85 m) corresponding position. Therefore, the ninth column (r) in the third table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on a closest distance (R=0.85 m) object, and the 10th column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on the closest distance (R=0.85 m) object to an in-focus state at the object distance in the second column. Furthermore, the ninth column (bf) in the fourth table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the closest corresponding position, and the object is located at an object distance in the second column, and the 10th column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on the closest distance (R=0.85 m) object to an in-focus state at the object distance in the second column.

From the above formulas, since the conversion coefficient in the direction of rotation is calculated by K_(a) =ΔBf/Δa (where Δa: the amount of rotation for focusing), and the correction coefficient μis calculated by μ=ΔBf/(1-K_(a) /γ_(a)), the value of the conversion coefficient K_(a) (eighth row, fourth column in first table: 0.175) when the focusing lens unit is moved from an in-focus state on the infinity object to an in-focus state at the object distance (R=0.85 m) in Table 6 is calculated by K_(a) =1.75/10.0 =0.175 using ΔBf=1.75 and Δa=10.0. On the other hand, the value of the correction coefficient μ (eighth row, fourth column in second table: -1.00) is calculated as μ=-1.00 using ΔBf=1.75, K_(a) =0.175, and γ_(a) =0.064.

                                      TABLE 6                                      __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of                                                              Rotation and Correction Coefficient μ: (l) at Wide-angle End (36.0          mm)                                                                            of Embodiment of Japanese Patent Application Laid-Open No. 5-142475            f = 36.0 mm                                                                    __________________________________________________________________________            (R,ANGLE) =                                                                    .000                                                                               .000                                                                               10.000                                                                             1.912                                                                              5.000                                                                              3.379                                                                              3.000                                                                              4.821                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               .064                                                                               .000    .068    .077    .090                                        2  10.000  .069                                                                               .077                                                                               .000    .089    .105                                        3  5.000   .078    .090                                                                               .105                                                                               .000    .122                                        4  3.000   .093    .108    .124                                                                               .142                                                                               .000                                        5  2.000   .110    .127    .144    .163                                        6  1.500   .126    .145    .163    .183                                        7  1.000   .158    .180    .200    .221                                        8  .850    .175    .197    .219    .241                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.13                                                                               -1.08                                                                              -.26                                                                               -.95                                                                               -.43                                                                               -1.18                                       2  10.000                                                                             .13 -1.71                                                                              .00 .00 -.13                                                                               -.86                                                                               -.31                                                                               -1.19                                       3  5.000                                                                              .26 -1.14                                                                              .13 -.77                                                                               .00 .00 -.18                                                                               -1.30                                       4  3.000                                                                              .45 -.97                                                                               .31 -.78                                                                               .18 -1.00                                                                              .00 .00                                         5  2.000                                                                              .68 -.94                                                                               .55 -.84                                                                               .41 -1.11                                                                              .23 -1.53                                       6  1.500                                                                              .93 -.94                                                                               .79 -.90                                                                               .65 -1.18                                                                              .47 -1.59                                       7  1.000                                                                              1.45                                                                               -.98                                                                               1.31                                                                               -.98                                                                               1.16                                                                               -1.29                                                                              .97 -1.71                                       8  .850                                                                               1.75                                                                               -1.00                                                                              1.60                                                                               -1.02                                                                              1.45                                                                               -1.34                                                                              1.25                                                                               -1.77                                       __________________________________________________________________________            (R,ANGLE) =                                                                    2.000                                                                              6.225                                                                              1.500                                                                              7.365                                                                              1.000                                                                              9.192                                                                              .850                                                                               10.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    .104    .117    .141    .153                                        2  10.000  .121    .136    .162    .175                                        3  5.000   .140    .155    .182    .196                                        4  3.000   .160    .176    .205    .219                                        5  2.000                                                                              .182                                                                               .000    .200    .231    .246                                        6  1.500   .204                                                                               .223                                                                               .000    .255    .271                                        7  1.000   .245    .265                                                                               .299                                                                               .000    .318                                        8  .850    .266    .287    .324                                                                               .346                                                                               .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -.65                                                                               -1.51                                                                              -.86                                                                               -1.82                                                                              -1.30                                                                              -2.46                                                                              -1.53                                                                              -2.74                                       2  10.000                                                                             -.52                                                                               -1.57                                                                              -.74                                                                               -1.91                                                                              -1.18                                                                              -2.58                                                                              -1.41                                                                              -2.86                                       3  5.000                                                                              -.40                                                                               -1.69                                                                              -.62                                                                               -2.03                                                                              -1.06                                                                              -2.72                                                                              -1.30                                                                              -2.99                                       4  3.000                                                                              -.22                                                                               -1.79                                                                              -.45                                                                               -2.14                                                                              -.90                                                                               -2.85                                                                              -1.14                                                                              -3.11                                       5  2.000                                                                              .00 .00 -.23                                                                               -2.24                                                                              -.69                                                                               -3.00                                                                              -.93                                                                               -3.22                                       6  1.500                                                                              .23 -1.97                                                                              .00 .00 -.47                                                                               -3.15                                                                              -.71                                                                               -3.29                                       7  1.000                                                                              .73 -2.13                                                                              .48 -2.55                                                                              .00 .00 -.26                                                                               -3.16                                       8  .850                                                                               1.00                                                                               -2.19                                                                              .76 -2.62                                                                              .26 -3.15                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.aO /γ.sub.aO = 2.75, K.sub.aK      /γ.sub.aK = 0.44                                                   

                                      TABLE 7                                      __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of                                                              Rotation and Correction Coefficient μ: (l) at Middle Position (50.0         mm)                                                                            of Embodiment of Japanese Patent Application Laid-Open No. 5-142475            f = 50.0 mm                                                                    __________________________________________________________________________            (R,ANGLE) =                                                                    .000                                                                               .000                                                                               10.000                                                                             1.972                                                                              5.000                                                                              3.373                                                                              3.000                                                                              4.821                                       POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000                                                                               .102                                                                               .000    .126    .146    .169                                        2  10.000  .128                                                                               .157                                                                               .000    .178    .203                                        3  5.000   .152    .182                                                                               .204                                                                               .000    .231                                        4  3.000   .180    .212    .236                                                                               .265                                                                               .000                                        5  2.000   .213    .247    .274    .305                                        6  1.500   .244    .281    .310    .343                                        7  1.000   .308    .350    .383    .421                                        8  .850    .342    .387    .422    .462                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               .00 .00 -.25                                                                               -1.26                                                                              -.49                                                                               -1.74                                                                              -.82                                                                               -2.25                                       2  10.000                                                                             .25 -.98                                                                               .00 .00 -.25                                                                               -1.97                                                                              -.58                                                                               -2.45                                       3  5.000                                                                              .51 -1.04                                                                              .25 -1.61                                                                              .00 .00 -.33                                                                               -2.57                                       4  3.000                                                                              .87 -1.13                                                                              .60 -1.72                                                                              .34 -2.17                                                                              .00 .00                                         5  2.000                                                                              1.33                                                                               -1.22                                                                              1.06                                                                               -1.83                                                                              .79 -2.29                                                                              .43 -2.87                                       6  1.500                                                                              1.81                                                                               -1.29                                                                              1.53                                                                               -1.92                                                                              1.25                                                                               -2.41                                                                              .88 -3.02                                       7  1.000                                                                              2.84                                                                               -1.40                                                                              2.53                                                                               -2.06                                                                              2.24                                                                               -2.55                                                                              1.85                                                                               -3.15                                       8  .850                                                                               3.42                                                                               -1.45                                                                              3.11                                                                               -2.12                                                                              2.80                                                                               -2.62                                                                              2.39                                                                               -3.22                                       __________________________________________________________________________            (R,ANGLE) =                                                                    2.000                                                                              6.241                                                                              1.500                                                                              7.403                                                                              1.000                                                                              9.213                                                                              .850                                                                               10.000                                      POS                                                                               R   r   rs  r   rs  r   rs  r   rs                                          __________________________________________________________________________     1  .000    .194    .216    .256    .275                                        2  10.000  .230    .253    .296    .317                                        3  5.000   .259    .284    .330    .352                                        4  3.000   .296    .322    .372    .396                                        5  2.000                                                                              .338                                                                               .000    .365    .421    .446                                        6  1.500   .377                                                                               .407                                                                               .000    .470    .497                                        7  1.000   .461    500 .566                                                                               .000    .593                                        8  .850    .505    .546    .612                                                                               .638                                                                               .000                                        __________________________________________________________________________     POS                                                                               R   bf  l   bf  l   bf  l   bf  l                                           __________________________________________________________________________     1  .000                                                                               -1.21                                                                              -2.85                                                                              -1.60                                                                              -3.41                                                                              -2.36                                                                              -4.30                                                                              -2.75                                                                              -4.83                                       2  10.000                                                                             -.98                                                                               -3.06                                                                              -1.38                                                                              -3.64                                                                              -2.15                                                                              -4.50                                                                              -2.54                                                                              -5.06                                       3  5.000                                                                              -.74                                                                               -3.21                                                                              -1.15                                                                              -3.80                                                                              -1.93                                                                              -4.63                                                                              -2.34                                                                              -5.22                                       4  3.000                                                                              -.42                                                                               -3.39                                                                              -.83                                                                               -3.99                                                                              -1.63                                                                              -4.76                                                                              -2.05                                                                              -5.39                                       5  2.000                                                                              .00 .00 -.42                                                                               -4.15                                                                              -1.25                                                                              -4.87                                                                              -1.68                                                                              -5.58                                       6  1.500                                                                              .44 -3.78                                                                              .00 .00 -.85                                                                               -5.02                                                                              -1.29                                                                              -5.84                                       7  1.000                                                                              1.37                                                                               -3.74                                                                              .91 -3.96                                                                              .00 .00 -.47                                                                               -6.54                                       8  .850                                                                               1.90                                                                               -3.82                                                                              1.42                                                                               -4.16                                                                              .48 -5.98                                                                              .00 .00                                         __________________________________________________________________________      Condition Corresponding Values: K.sub.aO /γ.sub.aO = 3.36, K.sub.aK      /γ.sub.aK = 0.43                                                   

                                      TABLE 8                                      __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of                                                              Rotation and Correction Coefficient μ: (l) at Telephoto End                 (103.0 mm) of Embodiment of Japanese Patent Application                        Laid-Open No. 5-142475                                                         f = 103.0 mm                                                                   (R,ANGLE) =                                                                            .000                                                                               .000                                                                               10.000                                                                             1.975                                                                              5.000                                                                              3.379                                                                              3.000                                                                              4.821                                      POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000                                                                               .425                                                                               .000    .505    .560    .614                                       2   10.000  .548                                                                               .631                                                                               .000    .686    .741                                       3   5.000   .653    .738                                                                               .794                                                                               .000    .850                                       4   3.000   .784    .872    .930                                                                               .989                                                                               .000                                       5   2.000   .944    1.036   1.096   1.155                                      6   1.500   1.103   1.198   1.258   1.316                                      7   1.000   1.432   1.530   1.588   1.640                                      8   .850    1.618   1.715   1.771   1.818                                      __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               .00 .00 -1.00                                                                              -5.02                                                                              -1.89                                                                              -6.41                                                                              -2.96                                                                              -7.81                                      2   10.000                                                                             1.08                                                                               -3.76                                                                              .00 .00 -.96                                                                               -7.06                                                                              -2.11                                                                              -8.40                                      3   5.000                                                                              2.21                                                                               -4.12                                                                              1.04                                                                               -6.07                                                                              .00 .00 -1.23                                                                              -8.76                                      4   3.000                                                                              3.78                                                                               -4.48                                                                              2.48                                                                               -6.48                                                                              1.34                                                                               -7.84                                                                              .00 .00                                        5   2.000                                                                              5.88                                                                               -4.82                                                                              4.40                                                                               -6.85                                                                              3.12                                                                               -8.21                                                                              1.62                                                                               -9.63                                      6   1.500                                                                              8.12                                                                               -5.10                                                                              6.46                                                                               -7.18                                                                              5.02                                                                               -8.58                                                                              3.35                                                                               -10.10                                     7   1.000                                                                              13.17                                                                              -5.56                                                                              11.04                                                                              -7.74                                                                              9.23                                                                               -9.23                                                                              7.17                                                                               -10.88                                     8   .850                                                                               16.18                                                                              -5.77                                                                              13.77                                                                              -8.00                                                                              11.73                                                                              -9.53                                                                              9.41                                                                               -11.22                                     __________________________________________________________________________     (R,ANGLE) =                                                                            2.000                                                                              6.225                                                                              1.500                                                                              7.365                                                                              1.000                                                                              9.192                                                                              .850                                                                               10.000                                     POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000    .666    .707    .769    .794                                       2   10.000  .794    .835    .895    .919                                       3   5.000   .904    .945    1.003   1.026                                      4   3.000   1.043   1.082   1.136   1.157                                      5   2.000                                                                              1.207                                                                              .000    1.242   1.290   1.307                                      6   1.500   1.364                                                                              1.394                                                                              .000    1.436   1.451                                      7   1.000   1.678   1.701                                                                              1.736                                                                              .000    1.733                                      8   .850    1.850   1.867   1.882                                                                              1.856                                                                              .000                                       __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               -4.15                                                                              -9.25                                                                              -5.21                                                                              -10.58                                                                             -7.07                                                                              -12.68                                                                             -7.94                                                                              -13.89                                     2   10.000                                                                             -3.37                                                                              -9.85                                                                              -4.50                                                                              -11.22                                                                             -6.46                                                                              -13.33                                                                             -7.38                                                                              -14.62                                     3   5.000                                                                              -2.57                                                                              -10.27                                                                             -3.77                                                                              -11.71                                                                             -5.83                                                                              -13.81                                                                             -6.80                                                                              -15.21                                     4   3.000                                                                              -1.46                                                                              -10.78                                                                             -2.75                                                                              -12.32                                                                             -4.96                                                                              -14.36                                                                             -5.99                                                                              -15.91                                     5   2.000                                                                              .00 .00 -1.42                                                                              -13.04                                                                             -3.83                                                                              -14.87                                                                             -4.94                                                                              -16.71                                     6   1.500                                                                              1.56                                                                               -11.96                                                                             .00 .00 -2.62                                                                              -15.19                                                                             -3.82                                                                              -17.53                                     7   1.000                                                                              4.98                                                                               -12.75                                                                             3.11                                                                               -14.09                                                                             .00 .00 -1.40                                                                              -21.25                                     8   .850                                                                               6.98                                                                               -13.11                                                                             4.92                                                                               -14.48                                                                             1.52                                                                               -18.11                                                                             .00 .00                                        __________________________________________________________________________      Condition Corresponding Values: K.sub.aO /γ.sub.aO = 3.80, K.sub.aR      /γ.sub.aR = 0.43                                                   

As can be seen from Tables 6, 7, and 8 above, when a change in conversion coefficient K_(a) : (rs) (e.g., the fourth column in the first table) and a change in correction coefficient μ: (l) (e.g., the fourth column in the second table) at a given lens arrangement (e.g., at the infinity in-focus arrangement) are considered, the conversion coefficient K_(a) and the correction coefficient μ considerably change depending on the object positions. In particular, the conversion coefficient K_(a) has a larger value at the closest object side than that at the infinity object side. Since the conversion coefficient K_(a) in the direction of rotation is defined by K_(a) =ΔBf/Δa, the amount Δa of rotation for focusing at the infinity object side becomes larger than that at the closest object side relative to the defocus amount ΔBf.

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end (F=36.0), middle position (F=50.0), and telephoto end (F=103.0) in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 are as follows.

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity     Closest                                                           Arrangement K.sub.aO /γ.sub.aO                                                        Arrangement K.sub.aR /γ.sub.aR                     ______________________________________                                         Wide-angle End                                                                            2.75           0.44                                                 (F = 36.0)                                                                     Middle Position                                                                           3.36           0.43                                                 (F = 50.0)                                                                     Telephoto End                                                                             3.80           0.43                                                 (F = 103.0)                                                                    ______________________________________                                    

As described above, in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, since the change in conversion coefficient K_(a) is large, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) becomes large, and the value of the correction coefficient μ becomes close to that of the defocus amount ΔBf. In addition, the value of the correction coefficient μ largely changes depending on the object positions.

Therefore, as described in Japanese Patent Application Laid-Open No. 3-228006, under the condition that only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range (e.g., an infinity in-focus arrangement range), if the correction coefficient μ which changes largely is represented by only one value, a large error is included in the value of the conversion coefficient K_(a) which is calculated from the conversion coefficient γ_(a) and the correction coefficient μ. Therefore, when the lens driving amount Δa for focusing is finally calculated from the defocus amount ΔBf using the conversion coefficient K_(a), the lens driving amount includes an error, and an auto-focus operation cannot be accurately performed.

For example, upon calculation of the lens driving amount Δa for focusing with respect to a closest distance (R=0.85 m) object when the correction coefficient μ (which changes from -3.76 to -5.77 depending on the object distances) at the infinity in-focus arrangement at the telephoto end (F=103.0) is represented by the value (μ=-4.82) at the middle object distance (R=2.0 m), the lens driving amount Δa for focusing is calculated as Δa=8.74 by substituting ΔBf=16.18, γ_(a) =0.425, and μ=-4.82. The actual lens driving amount for focusing from the state of the infinity in-focus arrangement at the telephoto end (F=103.0) to the closest distance (R=0.85 m) object is Δa=10.0 from (R, ANGLE)=(0.85, 10.0) in the upper right portion of the third table in Table 8. Therefore, an error as large as -12.6% is produced between the actual value and the calculated value Δa=8.74 of the lens driving amount for focusing.

Similarly, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/γ_(a) (1-ΔBf/μ), and errors from the actual lens driving amounts are then calculated, the following large values are obtained.

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                             -4.4%         -13.0%                                               (F = 36.0)                                                                     Middle Position                                                                           -11.8%         -12.0%                                               (F = 50.0)                                                                     Telephoto End                                                                             -12.6%         -14.6%                                               (F = 103.0)                                                                    ______________________________________                                    

Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (R=2.0 m), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (R=3.0 m).

Finally, Table 9 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 1) of the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and a displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

The upper table in Table 9 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.0, 2.0, 1.5, 1.0, and 0.85 m) in the respective zooming states of the focal lengths (F=36.0, 50.0, 60.0, 70.0, 85.0, and 103.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and the photographing distances. In the lower table, (F) is the focal length (mm) of the entire system, (R) is the photographing distance (m), and (DX) is the amount (mm) of movement, in the direction of the optical axis, of each of the first, second, third, and fourth lens units in turn from the right side (movement toward the object side is represented by a positive value).

                                      TABLE 9                                      __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Embodiment                                    of Japanese Patent Application Laid-Open No. 5-142475                                  0.85 m                                                                              1.00 m                                                                              1.50 m                                                                              2.00 m                                                                              3.00 m                                                                              5.00 m                                        __________________________________________________________________________     F 36.000 Bf                                                                            .000 .000 .000 .000 .000 .000                                          F 50.000 Bf                                                                            .000 .012 .015 .005 .000 -.001                                         F 60.000 Bf                                                                            .000 .005 .022 .017 -.001                                                                               -.007                                         F 70.000 Bf                                                                            .000 -.006                                                                               .001 .010 .008 -.007                                         F 85.000 Bf                                                                            .000 -.015                                                                               -.024                                                                               -.024                                                                               -.010                                                                               .005                                          F 103.000 Bf                                                                           .000 .000 .000 .000 .000 .000                                            ANGLE DA                                                                             10.000                                                                              9.192                                                                               7.365                                                                               6.225                                                                               4.821                                                                               3.379                                         F 36.000 DX                                                                            .000 1.037                                                                               .000 .000 R                                                                              0.85 m                                             F 50.000 DX                                                                            .000 1.483                                                                               .000 .000 R                                                                              0.85 m                                             F 60.000 DX                                                                            .000 1.872                                                                               .000 .000 R                                                                              0.85 m                                             F 70.000 DX                                                                            .000 2.311                                                                               .000 .000 R                                                                              0.85 m                                             F 85.000 DX                                                                            .000 3.049                                                                               .000 .000 R                                                                              0.85 m                                             F 103.000 DX                                                                           .000 4.080                                                                               .000 .000 R                                                                              0.85 m                                             F 36.000 DX                                                                            .000 .875 .000 .000 R                                                                              1.00 m                                             F 50.000 DX                                                                            .000 1.255                                                                               .000 .000 R                                                                              1.00 m                                             F 60.000 DX                                                                            .000 1.599                                                                               .000 .000 R                                                                              1.00 m                                             F 70.000 DX                                                                            .000 1.993                                                                               .000 .000 R                                                                              1.00 m                                             F 85.000 DX                                                                            .000 2.661                                                                               .000 .000 R                                                                              1.00 m                                             F 103.000 DX                                                                           .000 3.609                                                                               .000 .000 R                                                                              1.00 m                                             F 36.000 DX                                                                            .000 .576 .000 .000 R                                                                              1.50 m                                             F 50.000 DX                                                                            .000 .834 .000 .000 R                                                                              1.50 m                                             F 60.000 DX                                                                            .000 1.072                                                                               .000 .000 R                                                                              1.50 m                                             F 70.000 DX                                                                            .000 1.365                                                                               .000 .000 R                                                                              1.50 m                                             F 85.000 DX                                                                            .000 1.879                                                                               .000 .000 R                                                                              1.50 m                                             F 103.000 DX                                                                           .000 2.636                                                                               .000 .000 R                                                                              1.50 m                                             F 36.000 DX                                                                            .000 .429 .000 .000 R                                                                              2.00 m                                             F 50.000 DX                                                                            .000 .629 .000 .000 R                                                                              2.00 m                                             F 60.000 DX                                                                            .000 .810 .000 .000 R                                                                              2.00 m                                             F 70.000 DX                                                                            .000 1.037                                                                               .000 .000 R                                                                              2.00 m                                             F 85.000 DX                                                                            .000 1.457                                                                               .000 .000 R                                                                              2.00 m                                             F 103.000 DX                                                                           .000 2.090                                                                               .000 .000 R                                                                              2.00 m                                             F 36.000 DX                                                                            .000 .285 .000 .000 R                                                                              3.00 m                                             F 50.000 DX                                                                            .000 .422 .000 .000 R                                                                              3.00 m                                             F 60.000 DX                                                                            .000 .551 .000 .000 R                                                                              3.00 m                                             F 70.000 DX                                                                            .000 .703 .000 .000 R                                                                              3.00 m                                             F 85.000 DX                                                                            .000 1.004                                                                               .000 .000 R                                                                              3.00 m                                             F 103.000 DX                                                                           .000 1.488                                                                               .000 .000 R                                                                              3.00 m                                             F 36.000 DX                                                                            .000 .170 .000 .000 R                                                                              5.00 m                                             F 50.000 DX                                                                            .000 .254 .000 .000 R                                                                              5.00 m                                             F 60.000 DX                                                                            .000 .336 .000 .000 R                                                                              5.00 m                                             F 70.000 DX                                                                            .000 .434 .000 .000 R                                                                              5.00 m                                             F 85.000 DX                                                                            .000 .618 .000 .000 R                                                                              5.00 m                                             F 103.000 DX                                                                           .000 .951 .000 .000 R                                                                              5.00 m                                             __________________________________________________________________________

SUMMARY OF THE INVENTION

It is, therefore, an object of the present invention to provide a zoom lens which can suppress changes in conversion coefficient γ_(a) and correction coefficient μ above even when the focus cam is used for achieving manual focusing, can suppress the storage capacity by reducing the number of data of the conversion coefficient γ_(a) and correction coefficient μ to be stored in the storage means, can eliminate an error upon calculation of the lens driving amount Δa for focusing from the defocus amount ΔBf using the conversion coefficient K_(a), and can achieve accurate auto-focusing.

According to the present invention, in a zoom lens system in which the movement locus of a focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam so as to achieve an in-focus state by a substantially constant amount of rotation for an identical object distance independently of a zooming state upon expression of a predetermined movement locus for zooming by the amount of movement, in the direction of the optical axis, of lens units, and the angle of rotation of a rotatable lens barrel, when the ratios (dBf/dx) of the amount dBf of infinitesimal movement of the imaging plane to the amount dx of infinitesimal movement, in the direction of the optical axis, of the focusing lens unit at the infinity and closest in-focus points are respectively represented by γ_(xO) and γ_(xR), the amounts of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end and the telephoto end are respectively represented by Δx_(WR) and Δx_(TR), and the amount of rotation of the focusing lens unit on the focus cam corresponding to zooming from the wide-angle end to the telephoto end and the amount of rotation corresponding to focusing from the infinity in-focus state to the closest in-focus state are respectively represented by a_(z) and a_(F), the zoom lens satisfies conditional formulas (1), (2), and (3) below at least at the telephoto end:

    0.60<γ.sub.xR /γ.sub.xO <1.70                  (1)

    0.50<Δx.sub.TR /Δx.sub.WR <2.00                (2)

    0.30<|a.sub.F /a.sub.z |<2.50            (3)

It is preferable that when the ratios (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane with respect to the angle da of infinitesimal rotation of the focusing lens unit on the focus cam at the infinity and closest in-focus points are respectively represented by γ_(aO) and γ_(aR), the zoom lens satisfies the following formula at least at the wide-angle end and the telephoto end:

    0.50<γ.sub.aR /γ.sub.aO <2.00.

Furthermore, it is preferable that when the conversion coefficients K_(a), which are used when the focusing lens unit are located at the lens arrangements corresponding to the infinity and closest in-focus states and are expressed by K_(a) =ΔBf/Δa, are respectively represented by K_(aO) and K_(aR), the zoom lens satisfies the following formulas at least at the wide-angle end and the telephoto end:

    0.70<K.sub.aO /γ.sub.aO <1.80

    0.60<K.sub.aR /γ.sub.aR <1.60

where

ΔBf: the defocus amount between the imaging position of an object at an arbitrary position and a predetermined imaging point position

Δa: the angle of rotation of the focusing lens unit on the focus cam required for attaining an in-focus state on the object.

In the present invention, since the above-mentioned conditional formulas are satisfied, even when the focus cam is used to achieve so-called manual focusing, changes in conversion coefficient γ_(a) and correction coefficient μ required for realizing accurate auto-focusing can be reduced. For this reason, the number of data of the conversion coefficient γ_(a) and correction coefficient μ to be stored in the storage means can be reduced. Furthermore, since the change in correction coefficient μ is small, an error upon calculation of the lens driving amount Δa for focusing from the defocus amount ΔBf using the conversion coefficient K_(a) is small, and accurate auto-focusing can be realized.

As described above, when the zoom lens system is constituted by n lens units, and its k-th lens unit is used as a focusing lens unit, the conversion coefficient γ_(x) associated with the direction of the optical axis of the focusing lens unit (the ratio dBf/dx of the amount dBf of infinitesimal movement of the imaging plane to the amount dx of infinitesimal movement in the direction of the optical axis) is expressed using the imaging magnifications β of the respective lens units as follows:

    γ.sub.x =(1-β.sub.k.sup.2)β.sub.k+1.sup.2 β.sub.k+2.sup.2 . . . β.sub.n.sup.2.

Therefore, the rate of change, from the infinity in-focus value (γ_(xO)) to the closest in-focus value (γ_(xR)), of the conversion coefficient γ_(x) associated with the direction of the optical axis can be expressed using the imaging magnifications β_(Ok) and β_(Rk) of the focusing lens unit at the infinity and closest in-focus points as follows:

    γ.sub.xR /γ.sub.xO =(1-β.sub.Rk.sup.2)/(1-β.sub.Ok.sup.2)

On the other hand, the conversion coefficient γ_(a) associated with the direction of rotation of the focusing lens unit (the ratio dBf/da of the amount dBf of infinitesimal movement of the imaging plane to the angle da of infinitesimal rotation) can be expressed by:

    γ.sub.a =γ.sub.x ·(dx/da)

where dx/da is the slope of the focus cam. For this reason, the rate of change, from the infinity in-focus value (γ_(aO)) to the closest in-focus value (γ_(aR)), of the conversion coefficient γ_(a) associated with the direction of rotation of the focusing lens unit can be expressed using slopes (dx/da)_(O) and (dx/da)_(R) at the infinity and closest corresponding positions on the focus cam as follows:

    γ.sub.aR /γ.sub.aO =(γ.sub.xR /γ.sub.xO)·((dx/da).sub.R /(dx/da).sub.O).

Therefore, like in the present invention, in the zoom lens system in which the value of the conversion coefficient γ_(x) associated with the amount x of movement, in the direction of the optical axis, of the focusing lens unit does not vary much between the closest in-focus state and the infinity in-focus state, the ratio of the amount a_(F) of rotation of the focusing lens unit on the focus cam corresponding to focusing from the infinity in-focus state to the closest in-focus state and the amount a_(Z) of rotation corresponding to zooming from the wide-angle end to the telephoto end is set to be such a value that the slope (dx/da) on the focus cam does not vary much between the infinity and closest corresponding positions, thereby compressing the change in conversion coefficient γ_(a) associated with the direction of rotation.

According to the present invention, in a zoom lens in which the conversion coefficients γ_(xO) and γ_(xR) associated with the amount x of movement, in the direction of the optical axis, of the focusing lens unit at the infinity and closest in-focus points at at least the wide-angle and telephoto ends satisfies conditional formula (1), and in which the ratio between the amounts Δx_(WR) and Δx_(TR) of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end and the telephoto end satisfies conditional formula (2):

    0.60<γ.sub.xR /γ.sub.xO <1.70                  (1)

    0.50<Δx.sub.TR /Δx.sub.WR <2.00                (2)

the ratio of the amount a_(F) of rotation of the focusing lens unit on the focus cam corresponding to focusing from the infinity in-focus state to the closest in-focus state to the amount a_(Z) of rotation corresponding to zooming from the wide-angle end to the telephoto end is set to satisfy conditional formula (3):

    0.30<|a.sub.F /a.sub.Z |<2.50            (3)

so that, the final rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) associated with the direction of rotation can be set to be a small value which satisfies conditional formula (4) below:

    0.50<γ.sub.aR /γaO<2.00                        (4)

As described above, since the change in conversion coefficient γ_(a) can be reduced as compared to that in the conventional system, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means can be reduced.

For example, upon division of the focus range like in formula (a) (N >log(γ_(MAX) /γ_(MIN))log(1.2)) above, the following relation is satisfied:

    log(γ.sub.MAX /γ.sub.MIN)/log(1.2)<3.8

and the number of divisions can be smaller than in the conventional system. Therefore, cost can be reduced in terms of the storage capacity. Furthermore, as will be described later in the following description of the embodiments, since the changes in conversion coefficient K_(a) and correction coefficient μ are smaller than those in the conventional system, an error obtained upon calculation of the lens driving amount Aa for focusing from the defocus amount ΔBf using the conversion coefficient K_(a) is small, and an accurate auto-focusing operation can be realized.

The conditional formulas of the present invention will be explained below.

Conditional formula (1) is associated with the focusing lens unit in the zoom lens according to the present invention. When γ_(xR) /γ_(xO) is larger and smaller than the upper and lower limits of conditional formula (1), respectively, the value of the conversion coefficient γ_(x) associated with the amount x of movement, in the direction of the optical axis, of the focusing unit varies much between the infinity and closest in-focus states. For this reason, the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation, which rate is expressed as a product of the rate of change (γ_(xR) /γ_(xO)) of the conversion coefficient γ_(x) associated with the direction of the optical axis and the slope ratio ((dx/da)_(R) /(dx/da)_(O)) of the focus cam, becomes large. As a result, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases. In addition, since the changes in conversion coefficient K_(a) and correction coefficient μ become large, the error obtained upon calculation of the lens driving amount Δa from the defocus amount ΔBf is large, and an accurate auto-focusing operation cannot be performed.

Therefore, in order to further reduce the number of data to be stored in the storage means, and to achieve auto-focusing more accurately, the upper and lower limits of conditional formula (1) are preferably set as follows:

    0.75<γ.sub.xR /γ.sub.xO <1.50

Conditional formula (2) is associated with the ratio between the amounts of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end and the telephoto end. As will be described later in the description of the embodiments, this ratio is an amount which is associated with the ratio of the slope (dx/da)_(R) at the closest corresponding position to the slope (dx/da)_(O) at the infinity corresponding position on the focus cam. As the ratio between the two amounts of movement deviates from 1.0 more largely, changes in slope on the focus cam become larger. Therefore, when the ratio is larger and smaller than the upper and lower limits of conditional formula (2), respectively, changes in the slope on the focus cam between the infinity and closest corresponding positions, become large, and changes in the conversion coefficient γ_(a) associated with the direction of rotation, which rate is expressed as a product of the rate of change (γ_(xR) /γ_(xO)) of the conversion coefficient γ_(x) associated with the direction of the optical axis and the slope ratio ((dx/da)_(R) /(dx/da)_(O)) of the focus cam, become large. As a result, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases. In addition, since the changes in conversion coefficient K_(a) and correction coefficient μ become large, the error obtained upon calculation of the lens driving amount Δa from the defocus amount ΔBf is large, and an accurate auto-focusing operation cannot be performed.

Therefore, in order to further reduce the number of data to be stored in the storage means, and to achieve auto-focusing more accurately, the upper and lower limits of conditional formula (2) are preferably set as follows:

    0.65<Δx.sub.TR /Δx.sub.WR <1.60

Conditional formula (3) defines an appropriate ratio of the amount a_(F) of rotation of the focusing lens unit on the focus cam corresponding to focusing from the infinity in-focus state to the closest in-focus state to the amount a_(Z) of rotation corresponding to zooming from the wide-angle end to the telephoto end. This ratio ia an amount assoiated with changes in the slopes (dx/da)_(O) and (dx/da)_(R) at the infinity and closest corresponding positions on the focus cam, respectively, and when the ratio becomes smaler than 1.0, changes in the slope on the focus cum become smaller, on the contrary, when the ratio becomes larger than 1.0, changes in the slope on the focus cum become larger. In the case where the ratio is smaller than the lower limit of conditional formula (3), changes in the conversion coefficient γ_(a) associated with the direction of rotation, which rate is expressed as a product of the rate of change (γ_(xR) /γ_(xO)) of the conversion coefficient γ_(X) associated with the direction of the optical axis and the slope ratio ((dx/da)_(R) /(dx/da)_(O)) of the focus cam, become small. As a result, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means can be reduced. However, since the amount a_(F) of rotation for focusing becomes small relative to the amount a_(Z) of rotation corresponding to zooming from the wide-angle end to the telephoto end, the amount of rotation for so-called manual focusing becomes small, and it becomes difficult to manually attain accurate focusing. Therefore, a more desirable result can be obtained by setting the lower limit to 0.45.

On the contrary, when the ratio exceeds the upper limit of conditional formula (3), changes in the conversion coefficient γ_(a) associated with the direction of rotation, which rate is expressed as a product of the rate of change (γ_(xR) /γ_(xO)) of the conversion coefficient γ_(x) associated with the direction of the optical axis and the slope ratio ((dx/da)_(R) /(dx/da)_(O)) of the focus cam, become large. As a result, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases. In addition, since changes in μ are large, an error obtained upon calculation of the lens driving amount Δa from the defocus amount ΔBf is large, and an accurate auto-focusing operation cannot be performed.

Therefore, a more desirable result can be obtained by setting the upper limit to 1.80.

Conditional formula (4) is a condition associated with the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means, i.e., the number of divisions of the focus range. When γ_(aR) /γ_(aO) is smaller than the lower limit of conditional formula (4), the rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) becomes excessively smaller than 1.0, and changes in γ_(a) become large. As a result, since the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases, a storage means with a large storage capacity is required, resulting in an increase in cost.

On the contrary, when γ_(aR) /γ_(aO) exceeds the upper limit of conditional formula (4), the rate of change (γ_(aR) /γ_(aO)) of the conversion coefficient γ_(a) becomes excessively larger than 1.0. As a result, since the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means increases, a storage means with a large storage capacity is required.

Therefore, in order to reduce the number of data of the conversion coefficient γ_(a) and the correction coefficient μ to be stored in the storage means, the upper and lower limits of conditional formula (4) are preferably set as follows:

    0.60<γ.sub.aR /γ.sub.aO <1.70

In order to obtain a zoom lens which can perform auto-focusing more accurately, when the conversion coefficients K_(a) (=ΔBf/Δa) used when the focusing lens unit is located at the lens arrangements corresponding to the infinity in-focus state and the closest in-focus state are respectively represented by K_(aO) and K_(aR), the zoom lens preferably satisfies conditional formulas (5) and (6) below at least at the wide-angle end and the telephoto end:

    0.70<K.sub.aO /γ.sub.aO <1.80                        (5)

    0.60<K.sub.aR /γ.sub.aR <1.60                        (6)

Conditional formula (5) defines the rate of change of the conversion coefficient K_(a) in the direction of rotation upon a change in object position when the focusing lens unit corresponds to an arrangement in the infinity in-focus state. When the rate is smaller than the lower limit of conditional formula (5), the change in conversion coefficient K_(aO) upon a change in object position becomes too small as compared to the conversion coefficient γ_(aO) as the sensitivity associated with the movement in the direction of rotation of the focusing lens unit at the infinity in-focus point. Therefore, for example, when the conversion coefficient K_(aO) which changes upon a change in object position is expressed by a pair of a conversion coefficient γ_(aO) value and a correction coefficient μ_(aO) value on the basis of the relationship K_(aO) =γ_(aO) (1-ΔBf/μ_(aO)), a large error is produced in the value of the conversion coefficient K_(aO) calculated from the conversion coefficient γ_(aO) and the correction coefficient μ_(aO), thus disturbing accurate auto-focusing.

On the contrary, when the rate exceeds the upper limit of conditional formula (5), the change in conversion coefficient K_(aO) in the direction of rotation upon a change in object position becomes large as compared to the conversion coefficient γ_(aO) in the direction of rotation of the focusing lens unit at the infinity in-focus point. For this reason, when the conversion coefficient K_(aO) which changes upon a change in object position is expressed by a pair of a conversion coefficient γ_(aO) value and a correction coefficient μ_(aO) value, a large error is produced in the value of the conversion coefficient K_(aO) calculated from the conversion coefficient γ_(aO) and the correction coefficient μ_(aO).

In order to achieve auto-focusing more accurately, the upper and lower limits of conditional formula (5) are preferably set as follows:

    0.80<K.sub.aO /γ.sub.aO <1.50

Similarly, when the conversion coefficient K_(aO) changes from (K_(aO) /γ_(aO) <1) to (K_(aO) /γ_(aO) >1) upon a change in object position when the focusing lens unit corresponds to an arrangement in the infinity in-focus state, the sign of the correction coefficient μ_(aO) changes before and after (K_(aO) /γaO=1). As a result, when the conversion coefficient K_(aO) is expressed by a pair of a conversion coefficient γ_(aO) value and a correction coefficient μ_(aO) value, a large error is produced in the value of the conversion coefficient K_(aO) calculated from the conversion coefficient γ_(aO) and the correction coefficient μ_(aO). Therefore, the conversion coefficient K_(aO) does not preferably change too much after it exceeds (K_(aO) /γ_(aO) =1)Therefore, even when the conversion coefficient K_(aO) changes from (K_(aO) /γ_(aO) <1) to (K_(aO) /γ_(aO) >1), the zoom lens preferably satisfies the following conditional formula:

    0.80<K.sub.aO /γ.sub.aO <1.50

Conditional formula (6) defines the rate of change of the conversion coefficient K_(a) in the direction of rotation upon a change in object position when the focusing lens unit corresponds to an arrangement in the closest in-focus position. When the rate exceeds the upper limit of conditional formula (6), the change in conversion coefficient K_(aR) in the direction of rotation upon a change in object position becomes too large as compared to the conversion coefficient γ_(aR) as the sensitivity associated with the movement in the direction of rotation of the focusing lens unit at the closest in-focus point. Therefore, for example, when the conversion coefficient K_(aR) which changes upon a change in object position is expressed by a pair of a conversion coefficient γ_(aR) value and a correction coefficient μ_(aR) value on the basis of the relationship K_(aR) =γ_(aR) (1-ΔBf/μ_(aR)), a large error is produced in the value of the conversion coefficient K_(aR) calculated from the conversion coefficient γ_(aR) and the correction coefficient μ_(aR), thus disturbing accurate auto-focusing.

On the contrary, when the rate is smaller than the lower limit of conditional formula (6), the change in conversion coefficient K_(aR) in the direction of rotation upon a change in object position becomes small as compared to the conversion coefficient γ_(aR) in the direction of rotation of the focusing lens unit at the closest in-focus point. For this reason, when the conversion coefficient K_(aR) which changes upon a change in object position is expressed by a pair of a conversion coefficient γ_(aR) value and a correction coefficient μ_(aR) value, a large error is produced in the value of the conversion coefficient K_(aR) calculated from the conversion coefficient γ_(aR) and the correction coefficient μ_(aR).

In order to achieve auto-focusing more accurately, the upper and lower limits of conditional formula (6) are preferably set as follows:

    0.70<K.sub.aR /γ.sub.aR <1.40.

Similarly, when the conversion coefficient K_(aR) changes from (K_(aR) /γ_(aR) <1) to (K_(aR) /γ_(aR) >1) upon a change in object position when, the focusing lens unit corresponds to an arrangement in the closest in-focus state, the sign of the correction coefficient μ_(aR) changes before and after (K_(aR) /γ_(aR) =1). As a result, when the conversion coefficient K_(aR) is expressed by a pair of a conversion coefficient γ_(aR) value and a correction coefficient μ_(aR) value, a large error is produced in the value of the conversion coefficient K_(aR) calculated from the conversion coefficient γ_(aR) and the correction coefficient μ_(aR). Therefore, the conversion coefficient K_(aR) preferably does not change too much after it exceeds (K_(aR) γ/γ_(aR) =1).

Therefore, even when the conversion coefficient K_(aR) changes from (K_(aR) /γ_(aR) <1) to (K_(aR) /γ_(aR) >1), the zoom lens preferably satisfies the following conditional formula:

    0.70<K.sub.aR /γ.sub.aR <1.40.

The above and other objects, features and advantages of the present invention are explained hereinafter and may be better understood by reference to the drawings and the descriptive matter which follows.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a view showing the movement loci for zooming of a zoom lens according to the first embodiment of the present invention;

FIG. 1B is a view showing the shapes of a focus cam and a zoom compensation cam of a second lens unit in the zoom lens according to the first embodiment of the present invention; and

FIG. 2 is a view for explaining the shape of the focus cam in the zoom lens according to the first embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be described in detail hereinafter with reference to its embodiments.

First Embodiment!

A zoom lens of the first embodiment is a zoom lens which has a five-unit arrangement, i.e., positive, negative, negative, positive, and positive lens units, and attains focusing by a negative second lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=1.50 m) to the amount of rotation for zooming from the wide-angle end (F=81.5) to the telephoto end (F=196.0) is set to be -1.00.

Table 10 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the first embodiment.

The upper table in Table 10 summarizes the focal length data, and the principal point interval data relating to six zooming states of the respective lens units of the optical system corresponding to the first embodiment.

In this table, F1, F2, F3, F4, and F5 are respectively the focal lengths of first, second, third, fourth, and fifth lens units, and D1, D2, D3, D4, and D5 are respectively the principal point interval between the first and second lens units, the principal point interval between the second and third lens units, the principal point interval between the third and fourth lens units, the principal point interval between the fourth and fifrth lens units, and the principal point interval between the fifrth lens unit and a predetermined imaging plane in five zooming states (F=81.5 (1-POS), 105.0 (2-POS), 135.0 (3-POS), 150.0 (4-POS), and 196.0 mm (5-POS)).

The middle table in Table 10 summarizes spline sample data when the shape (a curve g_(2F) in FIG. 1B) of the focus cam in the second lens unit of the first embodiment, which is used for focusing, is expressed by the above-mentioned spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), (4), and (5) correspond to the first, second, third, fourth, and fifth lens units, respectively.

Furthermore, the lower table in Table 10 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=81.5, 105.0, 135.0, 150.0, and 196.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m) using the focus cam of the first embodiment. In the lower table in Table 10, since the amount of rotation for zooming from the wide-angle end (F=81.5) to the telephoto end (F=196.0) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=1.50 m) is set to be -10.0, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the first embodiment is -1.00.

                                      TABLE 10                                     __________________________________________________________________________     First Embodiment f = 81.5 to 196.0                                             (Rotation Amount Ratio: a.sub.F /a.sub.Z = -1.00)                              Focal lengths and Principal Point Intervals of                                 Lens Units of Second Embodiment                                                          1-POS                                                                               2-POS                                                                               3-POS                                                                               4-POS                                                                               5-POS                                            __________________________________________________________________________             F 81.5000                                                                             105.0000                                                                            135.0000                                                                            150.0000                                                                            196.0000                                         F1 126.0000                                                                            D1                                                                               14.7057                                                                             28.4458                                                                             39.0422                                                                             42.7524                                                                             50.5918                                          F2 -115.0000                                                                           D2                                                                               29.0000                                                                             29.0000                                                                             29.0000                                                                             29.0000                                                                             29.0000                                          F3 -59.0000                                                                            D3                                                                               32.7254                                                                             27.4883                                                                             20.8004                                                                             17.4555                                                                             7.1940                                           F4 93.0000                                                                             D4                                                                               13.8546                                                                             5.3516                                                                              1.4431                                                                              1.0778                                                                              3.4999                                           F5 110.0000                                                                            D5                                                                               110.3381                                                                            110.3381                                                                            110.3381                                                                            110.3381                                                                            110.3381                                         __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point)                            Corresponding to Second Embodiment                                                 ANGLE                                                                               (1)  (2)  (3)  (4)  (5)                                               __________________________________________________________________________      1  -11.0000                                                                            .0000                                                                               -14.7597                                                                            .0000                                                                               .0000                                                                               .0000                                              2  -10.0000                                                                            .0000                                                                               -13.5443                                                                            .0000                                                                               .0000                                                                               .0000                                              3  -8.4248                                                                             .0000                                                                               -11.5718                                                                            .0000                                                                               .0000                                                                               .0000                                              4  -6.8481                                                                             .0000                                                                               -9.4972                                                                             .0000                                                                               .0000                                                                               .0000                                              5  -5.2113                                                                             .0000                                                                               -7.3123                                                                             .0000                                                                               .0000                                                                               .0000                                              6  -3.5289                                                                             .0000                                                                               -5.0080                                                                             .0000                                                                               .0000                                                                               .0000                                              7  -2.3838                                                                             .0000                                                                               -3.4006                                                                             .0000                                                                               .0000                                                                               .0000                                              8  .0000                                                                               .0000                                                                               .0000                                                                               .0000                                                                               .0000                                                                               .0000                                              9  1.5752                                                                              .0000                                                                               2.2632                                                                              .0000                                                                               .0000                                                                               .0000                                             10  3.1519                                                                              .0000                                                                               4.6385                                                                              .0000                                                                               .0000                                                                               .0000                                             11  4.7887                                                                              .0000                                                                               7.1348                                                                              .0000                                                                               .0000                                                                               .0000                                             12  6.4711                                                                              .0000                                                                               9.7615                                                                              .0000                                                                               .0000                                                                               .0000                                             13  7.6162                                                                              .0000                                                                               11.5903                                                                             .0000                                                                               .0000                                                                               .0000                                             14  10.0000                                                                             .0000                                                                               15.4503                                                                             .0000                                                                               .0000                                                                               .0000                                             15  11.0000                                                                             .0000                                                                               17.0953                                                                             .0000                                                                               .0000                                                                               .0000                                             __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation                          for Focusing of First Embodiment                                               (Rotation Amount Ratio: a.sub.F /a.sub.Z = -1.00)                                     Infinity          Amount of                                                    Correspond-                                                                             Photograph-                                                                             Rotation for                                          Focal Length                                                                          ing Position                                                                            ing Distance                                                                            Focusing                                              __________________________________________________________________________     81.5 mm                                                                               .0000    5.00 m   -2.384                                                105.0 mm                                                                              2.0000   3.50 m   -3.529                                                135.0 mm                                                                              4.9000   2.50 m   -5.211                                                150.0 mm                                                                              6.3000   2.00 m   -6.848                                                196.0 mm                                                                              10.0000  1.70 m   -8.425                                                                1.50 m   -10.000                                               __________________________________________________________________________     Condition Corresponding Value (1)                                                             0.99 (wide-angle end)                                                                    0.90 (telephoto end)                                  Condition Corresponding Value (2)                                                             1.14                                                            Condition Corresponding Value (3)                                                             1.00                                                            Condition Corresponding Value (4)                                                             0.85 (wide-angle end)                                                                    0.78 (telephoto end)                                  Condition Corresponding Value (5)                                                             0.84 (wide-angle end)                                                                    0.94 (telephoto end)                                  Condition Corresponding Value (6)                                                             1.25 (wide-angle end)                                                                    1.07 (telephoto end)                                  __________________________________________________________________________

Table 11 below summarizes the numerical value data of the cams of the focusing lens unit in the first embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 10. In this table, (ANGLE) is the angle of rotation of the rotatable lens barrel, (2) is the amount (mm) of movement, in the direction of the optical axis, of the second lens unit, and (F) is the focal length (mm) of the entire system in an infinity in-focus state corresponding to the amount (ANGLE) of rotation.

                  TABLE 11                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit                                 in First Embodiment                                                            Focus Cam Numerical Value Data                                                 ANGLE          (2)          F                                                  ______________________________________                                         -10.0000       -13.5443     .0000                                              -9.5000        -12.9286     .0000                                              -9.0000        -12.3041     .0000                                              -8.5000        -11.6685     .0000                                              -8.0000        -11.0204     .0000                                              -7.5000        -10.3624     .0000                                              -7.0000        -9.6991      .0000                                              -6.5000        -9.0346      .0000                                              -6.0000        -8.3691      .0000                                              -5.5000        -7.7005      .0000                                              -5.0000        -7.0268      .0000                                              -4.5000        -6.3467      .0000                                              -4.0000        -5.6604      .0000                                              -3.5000        -4.9678      .0000                                              -3.0000        -4.2692      .0000                                              -2.5000        -3.5650      .0000                                              -2.0000        -2.8559      .0000                                              -1.5000        -2.1432      .0000                                              -1.0000        -1.4285      .0000                                              -.5000         -.7135       .0000                                              .0000          .0000        81.5000                                            .5000          .7119        87.4811                                            1.0000         1.4272       93.5880                                            1.5000         2.1528       99.4504                                            2.0000         2.8939       105.0000                                           2.5000         3.6475       110.2949                                           3.0000         4.4074       115.4532                                           3.5000         5.1680       120.5598                                           4.0000         5.9286       125.6692                                           4.5000         6.6919       130.8234                                           5.0000         7.4604       136.0537                                           5.5000         8.2358       141.3707                                           6.0000         9.0180       146.7503                                           6.5000         9.8073       152.1758                                           7.0000         10.6032      157.6764                                           7.5000         11.4038      163.3209                                           8.0000         12.2070      169.1739                                           8.5000         13.0126      175.2985                                           9.0000         13.8212      181.7598                                           9.5000         14.6336      188.6319                                           10.0000        15.4503      196.0000                                           ______________________________________                                         Zoom Compensation Cam Numerical Value Data                                     ANGLE          (2)          F                                                  ______________________________________                                         .0000          .0000        81.5000                                            .5000          -4.9081      87.4811                                            1.0000         -9.3554      93.5880                                            1.5000         -13.2329     99.4504                                            2.0000         -16.6339     105.0000                                           2.5000         -19.6762     110.2949                                           3.0000         -22.4640     115.4532                                           3.5000         -25.0615     120.5598                                           4.0000         -27.5107     125.6692                                           4.5000         -29.8440     130.8234                                           5.0000         -32.0842     136.0537                                           5.5000         -34.2441     141.3707                                           6.0000         -36.3252     146.7503                                           6.5000         -38.3315     152.1758                                           7.0000         -40.2758     157.6764                                           7.5000         -42.1745     163.3209                                           8.0000         -44.0391     169.1739                                           8.5000         -45.8794     175.2985                                           9.0000         -47.7042     181.7598                                           9.5000         -49.5210     188.6319                                           10.0000        -51.3364     196.0000                                           ______________________________________                                    

The left table in Table 11 summarizes the numerical value data of the focus cam of the first embodiment, and the right table in Table 11 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amount (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) coincides with the movement locus (a curve g₂ in FIG. 1A) of the second lens unit calculated using the paraxial data in the upper table in Table 10.

Therefore, the zoom compensation cam (a curve g_(2H) in FIG. 1B) is determined by subtracting the focus cam (the curve g_(2F) in FIG. 1B) from the movement locus (the curve g₂ in FIG. 1A) upon zooming of the second lens unit determined by the paraxial data in the upper table in Table 10.

FIGS. 1A and 1B and FIG. 2 will be briefly described below.

FIG. 1A shows the paraxial arrangement and the movement loci upon zooming of the zoom lens according to the first embodiment, and FIG. 1B shows the shapes of the focus cam and the zoom compensation cam of the second lens unit of this embodiment. Referring to FIGS. 1A and 1B, G1, G2, G3, G4, and G5 respectively represent the first, second, third, fourth, and fifth lens units, and g₁, g₂, g₃, g₄, and g₅ respectively represent the movement loci upon zooming of the first, second, third, fourth, and fifth lens units. In addition, g_(2F) and g₂, respectively represent the shapes of the focus cam and the zoom compensation cam of the second lens unit. As described above, a shape obtained by synthesizing the focus cam g_(2F) and the zoom compensation cam g_(2H) of the second lens unit coincides with the movement locus g₂ of the second lens unit.

FIG. 2 is a view for explaining the shape of the focus cam g_(2F) of the first embodiment. Referring to FIG. 2, (f=81.5; R=un) and (f=81.5; R=1.5) respectively represent the in-focus positions at the infinity and the closest distance (R=1.50 m) at the wide-angle end, and coordinate positions (x; a) on the focus cam are respectively (x; a)=(0; 0) and (x; a)=(-13.544; -10.0). On the other hand, (f=196; R=un) and (f=196; R=1.5) respectively represent the in-focus positions at the infinity and the closest distance (R=1.50 m) at the telephoto end, and coordinate positions (x; a) on the focus cam are respectively (x; a)=(15.450; 10) and (x; a)=(0; 0).

Upon zooming from the wide-angle end to the telephoto end, the second lens unit moves on the focus cam g₂ F from the coordinate position (0; 0) to the coordinate position (15.450; 10) for an infinity object, and from the coordinate position (-13.544; -10.0) to the coordinate position (0; 0) for a closest distance object. Therefore, the second lens unit moves by 10.0 in the direction of rotation (the direction of an axis a) in both the cases. On the other hand, upon focusing from the infinity arrangement to the closest distance object, the second lens unit moves on the focus cam g_(2F) from the coordinate position (0; 0) to the coordinate position (-13.544; -10.0) at the wide-angle end, and from the coordinate position (15.450; 10) to the coordinate position (0; 0) at the telephoto end. Therefore, the second lens unit moves by -10.0 in the direction of rotation (the direction of the axis a) at these ends. In contrast to this, in the direction of the optical axis (the direction of an axis x), the second lens unit moves by -13.544 at the wide-angle end, and by -15.450 at the telephoto end.

Since the shape of the focus cam g_(2F) is determined by interpolating the coordinates (f=81.5; R=1.5), (f=81.5; R=un), (f=196; R=1.5), and (f=196; R =un) by the spline function, the change in slope (dx/da) of the focus cam g_(2F), becomes larger as the absolute value of the x-coordinate of (f=81.5; R=1.5) is smaller or as the absolute value of the x-coordinate of (f=196; R=un) is larger. More specifically, as the ratio (Δx_(TR) /Δx_(WR)) between the amounts Δx_(TR) and Δx_(WR) of movement, in the direction of the optical axis, of the focusing lens unit required for focusing from the infinity position to the closest distance position at the wide-angle end or telephoto end is larger, the change in slope (dx/da) of the focus cam becomes larger.

Tables 12, 13, and 14 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(x) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=81.5), the middle position (F=135.0), and the telephoto end (F=196.0) according to the first embodiment, respectively. In these tables, (R) on the left side is the photographing distance (m), (ANG) is the amount of rotation on the focus cam upon focusing to the respective photographing distances, and 1), 2), 3), 4), and 5) on the right side respectively represent the first, second, third, fourth, and fifth lens units. Also, in these tables, the first table summarizes the amount DX (mm) of movement for focusing in the direction of the optical axis upon focusing to the respective photographing distances (R=10.0, 5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m) (note that movement toward the object side is positive). The second table summarizes the imaging magnifications β_(K) of the respective lens units in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m). The third table summarizes the conversion coefficient γ_(x) associated with the direction of the optical axis of the focusing lens unit in an in-focus state at,the respective photographing distances (R=10.0, 5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m). Furthermore, the fourth table summarizes the slope (dx/da) of the focus cam at the positions, on the focus cam, corresponding to an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m), and the fifth table summarizes the conversion coefficient γ_(a) associated with the direction of rotation of the focusing lens unit in an in-focus state at the respective photographing distances (R=10.0, 5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m).

                                      TABLE 12                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical                Axis at Wide-angle End (81.5 mm) in First Embodiment                           __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .000                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -1.150                                                                             1) .000                                                                             2) -1.643                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -2.384                                                                             1) .000                                                                             2) -3.401                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.500                                                                              ANG                                                                               -3.529                                                                             1) .000                                                                             2) -5.008                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -5.211                                                                             1) .000                                                                             2) -7.312                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -6.848                                                                             1) .000                                                                             2) -9.497                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.700                                                                              ANG                                                                               -8.425                                                                             1) .000                                                                             2) -11.572                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      R 1.500                                                                              ANG                                                                               -10.000                                                                            1) .000                                                                             2) -13.544                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Wide-angle                 End (81.5 mm) in First Embodiment                                              __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 31.033                                                                            3) -.018                                                                            4) 386.84                                                                           5) -.003                                     R 10.000                                                                             ANG                                                                               -1.150                                                                             1) -.013                                                                            2) 31.019                                                                            3) -.018                                                                            4) 386.84                                                                           5) -.003                                     R 5.000                                                                              ANG                                                                               -2.384                                                                             1) -.027                                                                            2) 31.003                                                                            3) -.018                                                                            4) 386.84                                                                           5) -.003                                     R 3.500                                                                              ANG                                                                               -3.529                                                                             1) -.040                                                                            2) 30.989                                                                            3) -.018                                                                            4) 386.84                                                                           5) -.003                                     R 2.500                                                                              ANG                                                                               -5.211                                                                             1) -.058                                                                            2) 30.969                                                                            3) -.018                                                                            4) 386.84                                                                           5) -.003                                     R 2.000                                                                              ANG                                                                               -6.848                                                                             1) -.075                                                                            2) 30.950                                                                            3) -.018                                                                            4) 386.84                                                                           5) -.003                                     R 1.700                                                                              ANG                                                                               -8.425                                                                             1) -.092                                                                            2) 30.932                                                                            3) -.018                                                                            4) 386.84                                                                           5) -.003                                     R 1.500                                                                              ANG                                                                               -10.000                                                                            1) -.107                                                                            2) 30.915                                                                            3) -.018                                                                            4) 386.84                                                                           5) -.003                                     __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction                 of Optical Axis at Wide-angle End (81.5 mm) in First Embodiment                __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -.418                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -1.150                                                                             1) .000                                                                             2) -.418                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -2.384                                                                             1) .000                                                                             2) -.417                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.500                                                                              ANG                                                                               -3.529                                                                             1) .000                                                                             2) -.417                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -5.211                                                                             1) .000                                                                             2) -.416                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -6.848                                                                             1) .000                                                                             2) -.416                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.700                                                                              ANG                                                                               -8.425                                                                             1) .000                                                                             2) -.415                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.500                                                                              ANG                                                                               -10.000                                                                            1) .000                                                                             2) -.415                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Wide-angle End (81.5 mm)                           in First Embodiment                                                            __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 1.425                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -1.150                                                                             1) .000                                                                             2) 1.430                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -2.384                                                                             1) .000                                                                             2) 1.416                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.500                                                                              ANG                                                                               -3.529                                                                             1) .000                                                                             2) 1.391                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -5.211                                                                             1) .000                                                                             2) 1.348                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -6.848                                                                             1) .000                                                                             2) 1.329                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.700                                                                              ANG                                                                               -8.425                                                                             1) .000                                                                             2) 1.288                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.500                                                                              ANG                                                                               -10.000                                                                            1) .000                                                                             2) 1.224                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction                 of Rotation at Wide-angle End (81.5 mm) in First Embodiment                    __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -.595                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -1.150                                                                             1) .000                                                                             2) -.597                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -2.384                                                                             1) .000                                                                             2) -.591                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.500                                                                              ANG                                                                               -3.529                                                                             1) .000                                                                             2) -.580                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -5.211                                                                             1) .000                                                                             2) -.561                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -6.848                                                                             1) .000                                                                             2) -.553                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.700                                                                              ANG                                                                               -8.425                                                                             1) .000                                                                             2) -.535                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.500                                                                              ANG                                                                               -10.000                                                                            1) .000                                                                             2) -.508                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 0.99,         γ.sub.aR /γ.sub.aO = 0.85                                    

                                      TABLE 13                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical                Axis at Middle Position (135.0 mm) in First Embodiment                         __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .000                                                                              3) .000                                                                             4) .000                                                                              5) .000                                     R 10.000                                                                             ANG                                                                               -1.142                                                                             1) .000                                                                             2) -1.745                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 5.000                                                                              ANG                                                                               -2.370                                                                             1) .000                                                                             2) -3.614                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 3.500                                                                              ANG                                                                               -3.516                                                                             1) .000                                                                             2) -5.323                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 2.500                                                                              ANG                                                                               -5.229                                                                             1) .000                                                                             2) -7.775                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 2.000                                                                              ANG                                                                               -6.857                                                                             1) .000                                                                             2) -10.101                                                                           3) .000                                                                             4) .000                                                                              5) .000                                     R 1.700                                                                              ANG                                                                               -8.427                                                                             1) .000                                                                             2) -12.312                                                                           3) .000                                                                             4) .000                                                                              5) .000                                     R 1.500                                                                              ANG                                                                               -9.960                                                                             1) .000                                                                             2) -14.414                                                                           3) .000                                                                             4) .000                                                                              5) .000                                     __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Middle Position            (135.0 mm) in First Embodiment                                                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 4.101                                                                             3) -.220                                                                            4) 386.98                                                                            5) -.003                                    R 10.000                                                                             ANG                                                                               -1.142                                                                             1) -.013                                                                            2) 4.086                                                                             3) -.220                                                                            4) 386.98                                                                            5) -.003                                    R 5.000                                                                              ANG                                                                               -2.370                                                                             1) -.027                                                                            2) 4.070                                                                             3) -.220                                                                            4) 386.98                                                                            5) -.003                                    R 3.500                                                                              ANG                                                                               -3.516                                                                             1) -.040                                                                            2) 4.055                                                                             3) -.220                                                                            4) 386.98                                                                            5) -.003                                    R 2.500                                                                              ANG                                                                               -5.229                                                                             1) -.058                                                                            2) 4.033                                                                             3) -.220                                                                            4) 386.98                                                                            5) -.003                                    R 2.000                                                                              ANG                                                                               -6.857                                                                             1) -.075                                                                            2) 4.013                                                                             3) -.220                                                                            4) 386.98                                                                            5) -.003                                    R 1.700                                                                              ANG                                                                               -8.427                                                                             1) -.092                                                                            2) 3.994                                                                             3) -.220                                                                            4) 386.98                                                                            5) -.003                                    R 1.500                                                                              ANG                                                                               -9.960                                                                             1) -.107                                                                            2) 3.976                                                                             3) -.220                                                                            4) 386.98                                                                            5) -.003                                    __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction                 of Optical Axis at Middle Position (135.0 mm) in First Embodiment              __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -1.080                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 10.000                                                                             ANG                                                                               -1.142                                                                             1) .000                                                                             2) -1.071                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 5.000                                                                              ANG                                                                               -2.370                                                                             1) .000                                                                             2) -1.062                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 3.500                                                                              ANG                                                                               -3.516                                                                             1) .000                                                                             2) -1.054                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 2.500                                                                              ANG                                                                               -5.229                                                                             1) .000                                                                             2) -1.042                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 2.000                                                                              ANG                                                                               -6.857                                                                             1) .000                                                                             2) -1.031                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 1.700                                                                              ANG                                                                               -8.427                                                                             1) .000                                                                             2) -1.021                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 1.500                                                                              ANG                                                                               -9.960                                                                             1) .000                                                                             2) -1.011                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     __________________________________________________________________________     Slope dx/da of Focus Cam at Middle Position (135.0 mm)                         in First Embodiment                                                            __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 1.541                                                                             3) .000                                                                             4) .000                                                                              5) .000                                     R 10.000                                                                             ANG                                                                               -1.142                                                                             1) .000                                                                             2) 1.521                                                                             3) .000                                                                             4) .000                                                                              5) .000                                     R 5.000                                                                              ANG                                                                               -2.370                                                                             1) .000                                                                             2) 1.516                                                                             3) .000                                                                             4) .000                                                                              5) .000                                     R 3.500                                                                              ANG                                                                               -3.516                                                                             1) .000                                                                             2) 1.458                                                                             3) .000                                                                             4) .000                                                                              5) .000                                     R 2.500                                                                              ANG                                                                               -5.229                                                                             1) .000                                                                             2) 1.428                                                                             3) .000                                                                             4) .000                                                                              5) .000                                     R 2.000                                                                              ANG                                                                               -6.857                                                                             1) .000                                                                             2) 1.423                                                                             3) .000                                                                             4) .000                                                                              5) .000                                     R 1.700                                                                              ANG                                                                               -8.427                                                                             1) .000                                                                             2) 1.391                                                                             3) .000                                                                             4) .000                                                                              5) .000                                     R 1.500                                                                              ANG                                                                               -9.960                                                                             1) .000                                                                             2) 1.352                                                                             3) .000                                                                             4) .000                                                                              5) .000                                     __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction                 of Rotation at Middle Position (135.0 mm) in First Embodiment                  __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -1.664                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 10.000                                                                             ANG                                                                               -1.142                                                                             1) .000                                                                             2) -1.629                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 5.000                                                                              ANG                                                                               -2.370                                                                             1) .000                                                                             2) -1.611                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 3.500                                                                              ANG                                                                               -3.516                                                                             1) .000                                                                             2) -1.537                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 2.500                                                                              ANG                                                                               -5.229                                                                             1) .000                                                                             2) -1.488                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 2.000                                                                              ANG                                                                               -6.857                                                                             1) .000                                                                             2) -1.467                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 1.700                                                                              ANG                                                                               -8.427                                                                             1) .000                                                                             2) -1.419                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     R 1.500                                                                              ANG                                                                               -9.960                                                                             1) .000                                                                             2) -1.367                                                                            3) .000                                                                             4) .000                                                                              5) .000                                     __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 0.94,         γ.sub.aR /γ.sub.aO = 0.82                                    

                                      TABLE 14                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical                Axis at Telephoto End (196.0 mm) in First Embodiment                           __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .000                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -1.145                                                                             1) .000                                                                             2) -1.863                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -2.384                                                                             1) .000                                                                             2) -3.860                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.500                                                                              ANG                                                                               -3.529                                                                             1) .000                                                                             2) -5.689                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -5.211                                                                             1) .000                                                                             2) -8.316                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -6.848                                                                             1) .000                                                                             2) -10.812                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      R 1.700                                                                              ANG                                                                               -8.425                                                                             1) .000                                                                             2) -13.187                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      R 1.500                                                                              ANG                                                                               -10.000                                                                            1) .000                                                                             2) -15.450                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Telephoto End              (196.0 mm) in First Embodiment                                                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) -.000                                                                            2) 2.905                                                                             3) -.450                                                                            4) 386.95                                                                           5) -.003                                     R 10.000                                                                             ANG                                                                               -1.145                                                                             1) -.013                                                                            2) 2.888                                                                             3) -.450                                                                            4) 386.95                                                                           5) -.003                                     R 5.000                                                                              ANG                                                                               -2.384                                                                             1) -.027                                                                            2) 2.871                                                                             3) -.450                                                                            4) 386.95                                                                           5) -.003                                     R 3.500                                                                              ANG                                                                               -3.529                                                                             1) -.040                                                                            2) 2.855                                                                             3) -.450                                                                            4) 386.95                                                                           5) -.003                                     R 2.500                                                                              ANG                                                                               -5.211                                                                             1) -.058                                                                            2) 2.832                                                                             3) -.450                                                                            4) 386.95                                                                           5) -.003                                     R 2.000                                                                              ANG                                                                               -6.848                                                                             1) -.075                                                                            2) 2.811                                                                             3) -.450                                                                            4) 386.95                                                                           5) -.003                                     R 1.700                                                                              ANG                                                                               -8.425                                                                             1) -.092                                                                            2) 2.790                                                                             3) -.450                                                                            4) 386.95                                                                           5) -.003                                     R 1.500                                                                              ANG                                                                               -10.000                                                                            1) -.107                                                                            2) 2.770                                                                             3) -.450                                                                            4) 386.98                                                                           5) -.003                                     __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction                 of Optical Axis at Telephoto End (196.0 mm) in First Embodiment                __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -2.133                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -1.145                                                                             1) .000                                                                             2) -2.106                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -2.384                                                                             1) .000                                                                             2) -2.077                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.500                                                                              ANG                                                                               -3.529                                                                             1) .000                                                                             2) -2.051                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -5.211                                                                             1) .000                                                                             2) -2.014                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -6.848                                                                             1) .000                                                                             2) -1.979                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.700                                                                              ANG                                                                               -8.425                                                                             1) .000                                                                             2) -1.946                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.500                                                                              ANG                                                                               -10.000                                                                            1) .000                                                                             2) -1.914                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Telephoto End (196.0 mm)                           in First Embodiment                                                            __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 1.638                                                                            3) .000                                                                             4) .000                                                                             5) .000                                       R 10.000                                                                             ANG                                                                               -1.145                                                                             1) .000                                                                             2) 1.619                                                                            3) .000                                                                             4) .000                                                                             5) .000                                       R 5.000                                                                              ANG                                                                               -2.384                                                                             1) .000                                                                             2) 1.605                                                                            3) .000                                                                             4) .000                                                                             5) .000                                       R 3.500                                                                              ANG                                                                               -3.529                                                                             1) .000                                                                             2) 1.585                                                                            3) .000                                                                             4) .000                                                                             5) .000                                       R 2.500                                                                              ANG                                                                               -5.211                                                                             1) .000                                                                             2) 1.538                                                                            3) .000                                                                             4) .000                                                                             5) .000                                       R 2.000                                                                              ANG                                                                               -6.848                                                                             1) .000                                                                             2) 1.522                                                                            3) .000                                                                             4) .000                                                                             5) .000                                       R 1.700                                                                              ANG                                                                               -8.425                                                                             1) .000                                                                             2) 1.471                                                                            3) .000                                                                             4) .000                                                                             5) .000                                       R 1.500                                                                              ANG                                                                               -10.000                                                                            1) .000                                                                             2) 1.425                                                                            3) .000                                                                             4) .000                                                                             5) .000                                       __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction                 of Rotation at Telephoto End (196.0 mm) in First Embodiment                    __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -3.494                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -1.145                                                                             1) .000                                                                             2) -3.409                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -2.384                                                                             1) .000                                                                             2) -3.335                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.500                                                                              ANG                                                                               -3.529                                                                             1) .000                                                                             2) -3.251                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -5.211                                                                             1) .000                                                                             2) -3.098                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -6.848                                                                             1) .000                                                                             2) -3.011                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.700                                                                              ANG                                                                               -8.425                                                                             1) .000                                                                             2) -2.862                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.500                                                                              ANG                                                                               -10.000                                                                            1) .000                                                                             2) -2.727                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 0.90,         γ.sub.aR /γ.sub.aO = 0.78                                    

As can be seen from Tables 12, 13, and 14, at each focal length, the value of the conversion coefficient γ_(x) associated with the direction of the optical axis, and the value of the slope (dx/da) of the focus cam decreases as the photographing distance becomes closer to the closest distance. However, since the degree of the decrease is small in any case, the width of changes in the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, becomes small.

From Tables 12, 13, and 14, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×0.85 at the wide-angle end (F=81.5), ×0.82 at the middle position (F=135.0), and ×0.78 at the telephoto end (F =196.0). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the first embodiment is calculated using formula (a), and is compared with that in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values:

Embodiment of Japanese Patent Application Laid-Open No. 5-142475

    N.sub.W >9.3 N.sub.M >10.1 N.sub.T >8.1

First Embodiment

    N.sub.W >0.9 N.sub.M >1.1 N.sub.T >1.4

Therefore, as can be understood from a comparison with the previously calculated values in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the values of the numbers N of divisions become very small.

As described above, in the zoom lens of the first embodiment, since the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation becomes much smaller than that in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Tables 15, 16, and 17 summarize the calculation results of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=81.5), middle position (F=135.0), and telephoto end (F=196.0) according to the first embodiment. In these tables, (R) is the object distance (m), (ANG) is the amount of rotation for focusing from the infinity corresponding position on the focus cam, (r) is the conversion coefficient γ_(a) in the direction of rotation, (rs) is the conversion coefficient K_(a), (bf) is the defocus amount (mm), and (l) is the correction coefficient μ. Each table has a matrix structure, and eight rows in the vertical direction indicated by (POS) represent the object positions (R=10.0, 5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m), and four pairs (R, ANGLE) in the horizontal direction represent the lens arrangements of the focusing lens unit.

More specifically, the position of the focusing lens in the first pair in the upper two tables in each of Tables 15, 16, and 17, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Therefore, the third column (r) in the first table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on an infinity object, and the fourth column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column. Furthermore, the third column (bf) in the second table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the infinity corresponding position, and an object is located at an object distance in the second column, and the fourth column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on an infinity object to an in-focus state at the object distance in the second column.

Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 15, 16, and 17, i.e., in the ninth and tenth columns is (R, ANGLE)=(1.50, -10.0), and it indicates that this position corresponds to the closest in-focus (R=1.50 m) corresponding position. Therefore, the ninth column (r) in the third table represents the value of the conversion coefficient γ_(a) in the direction of rotation when the focusing lens unit is focused on a closest distance (R=1.50 m) object, and the tenth column (rs) represents the value of the conversion coefficient K_(a) when the focusing lens unit is moved from an in-focus state on the closest distance (R=1.50 m) object to an in-focus state at the object distance in the second column. Furthermore, the ninth column (bf) in the fourth table represents the defocus amount ΔBf from a predetermined imaging position when the position of the focusing lens unit corresponds to the closest corresponding position, and the object is located at an object distance in the second column, and the tenth column (l) represents the value of the correction coefficient μ when the focusing lens unit is moved from an in-focus state on the closest distance (R=1.50 m) object to an in-focus state at the object distance in the second column.

As described above, since the conversion coefficient in the direction of rotation is calculated by K_(a) =ΔBf/Δa (where Δa: the amount of rotation for focusing), and the correction coefficient μ is calculated by μ=ΔBf/(1-K_(a) /γ_(a)), the value of the conversion coefficient K_(a) (eighth row, fourth column in first table: -0.500) when the focusing lens unit is moved from an in-focus state on the infinity object to an in-focus state at the object distance (R=1.50 m) in Table 15 is calculated by K_(a) =5.00/-10.0=-0.500 using ΔBf=5.00 and Δa=-10.0. On the other hand, the value of the correction coefficient μ (eighth row, fourth column in second table: 31.17) is calculated as μ=31.17 using ΔBf=5.00, K_(a) =-0.500, and γ_(a) =-0.595.

                                      TABLE 15                                     __________________________________________________________________________     Conversion Coefficients K.sub.a :(rs), γ.sub.a :(r) Associated with      Direction of Rotation and Correction                                           Coefficient μ: (l) at Wide-angle End (81.5 mm) of First Embodiment          f = 81.5 mm                                                                    __________________________________________________________________________     (R,ANGLE) =                                                                             .000                                                                               .000                                                                               10.000                                                                             -1.150                                                                             5.000                                                                              -2.384                                                                             3.500                                                                              -3.529                                    POS R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000 -.595                                                                              .000    -.606   -.615   -.621                                     2   10.000   -.588                                                                              -.597                                                                              .000    -.604   -.609                                     3   5.000    -.577   -.585                                                                              -.590                                                                              .000    -.594                                     4   3.500    -.565   -.572   -.577                                                                              -.580                                                                              .000                                      5   2.500    -.547   -.553   -.556   -.559                                     6   2.000    -.530   -.535   -.539   -.541                                     7   1.700    -.516   -.520   -.524   -.526                                     8   1.500    -.500   -.504   -.507   -.509                                     __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 .00 .00 -.70                                                                               47.15                                                                              -1.47                                                                              35.24                                                                              -2.19                                                                              30.93                                     2   10.000                                                                              .68 51.63                                                                              .00 .00 -.75                                                                               31.50                                                                              -1.45                                                                              28.75                                     3   5.000                                                                               1.38                                                                               44.50                                                                              .72 34.84                                                                              .00 .00 -.68                                                                               27.31                                     4   3.500                                                                               2.00                                                                               39.61                                                                              1.36                                                                               32.24                                                                              .66 28.60                                                                              .00 .00                                       5   2.500                                                                               2.85                                                                               35.31                                                                              2.24                                                                               30.06                                                                              1.57                                                                               27.38                                                                              .94 26.28                                     6   2.000                                                                               3.63                                                                               33.26                                                                              3.05                                                                               29.27                                                                              2.40                                                                               27.37                                                                              1.80                                                                               26.99                                     7   1.700                                                                               4.35                                                                               32.48                                                                              3.78                                                                               29.30                                                                              3.16                                                                               27.99                                                                              2.58                                                                               28.14                                     8   1.500                                                                               5.00                                                                               31.17                                                                              4.46                                                                               28.48                                                                              3.86                                                                               27.27                                                                              3.29                                                                               27.12                                     __________________________________________________________________________     (R,ANGLE) =                                                                             2.500                                                                              -5.211                                                                             2.000                                                                              -6.848                                                                             1.700                                                                              -8.425                                                                             1.500                                                                              -10.000                                   POS R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000     -.626   -.630   -.635   -.637                                     2   10.000   -.613   -.617   -.621   -.622                                     3   5.000    -.597   -.601   -.605   -.606                                     4   3.500    -.582   -.586   -.591   -.591                                     5   2.500                                                                               -.561                                                                              .000    -.566   -.572   -.571                                     6   2.000    -.545                                                                              -.553                                                                              .000    -.557   -.552                                     7   1.700    -.531   -.537                                                                              -.535                                                                              .000    -.528                                     8   1.500    -.512   -.515   -.511                                                                              -.509                                                                              .000                                      __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 -3.26                                                                              27.91                                                                              -4.32                                                                              30.71                                                                              -5.35                                                                              28.44                                                                              -6.37                                                                              25.33                                     2   10.000                                                                              -2.49                                                                              26.63                                                                              -3.51                                                                              30.39                                                                              -4.52                                                                              27.91                                                                              -5.50                                                                              24.73                                     3   5.000                                                                               -1.69                                                                              25.76                                                                              -2.68                                                                              30.89                                                                              -3.66                                                                              27.65                                                                              -4.61                                                                              24.20                                     4   3.500                                                                               -.98                                                                               25.09                                                                              -1.94                                                                              32.34                                                                              -2.89                                                                              27.46                                                                              -3.82                                                                              23.67                                     5   2.500                                                                               .00 .00 -.93                                                                               38.27                                                                              -1.84                                                                              26.34                                                                              -2.73                                                                              22.45                                     6   2.000                                                                               .89 31.64                                                                              .00 .00 -.88                                                                               21.36                                                                              -1.74                                                                              20.47                                     7   1.700                                                                               1.71                                                                               32.41                                                                              .85 29.84                                                                              .00 .00 -.83                                                                               21.49                                     8   1.500                                                                               2.45                                                                               28.60                                                                              1.62                                                                               23.84                                                                              .81 18.27                                                                              .00 .00                                       __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0  = 0.84, K.sub.a      /γ.sub.aR  = 1.25                                                  

                                      TABLE 16                                     __________________________________________________________________________     Conversion Coefficients K.sub.a :(rs), γ.sub.a :(r) Associated with      Direction of Rotation and Correction                                           Coefficient μ: (l) at Middle Position (135.0 mm) of First Embodiment        f = 135.0 mm                                                                   __________________________________________________________________________     (R,ANGLE) =                                                                             .000                                                                               .000                                                                               10.000                                                                             -1.142                                                                             5.000                                                                              -2.370                                                                             3.500                                                                              -3.516                                    POS R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000 -1.665                                                                             .000    -1.659  -1.663  -1.658                                    2   10.000   -1.629                                                                             -1.629                                                                             .000    -1.637  -1.629                                    3   5.000    -1.602  -1.607                                                                             -1.611                                                                             .000    -1.592                                    4   3.500    -1.571  -1.572  -1.565                                                                             -1.536                                                                             .000                                      5   2.500    -1.516  -1.513  -1.501  -1.483                                    6   2.000    -1.477  -1.475  -1.467  -1.458                                    7   1.700    -1.442  -1.441  -1.435  -1.429                                    8   1.500    -1.408  -1.407  -1.402  -1.397                                    __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 .00 .00 -1.89                                                                              103.84                                                                             -3.94                                                                              121.79                                                                             -5.83                                                                              73.40                                     2   10.000                                                                              1.86                                                                               85.97                                                                              .00 .00 -2.01                                                                              121.42                                                                             -3.87                                                                              -63.65                                    3   5.000                                                                               3.80                                                                               100.44                                                                             1.97                                                                               140.66                                                                             .00 .00 -1.82                                                                              50.18                                     4   3.500                                                                               5.52                                                                               97.88                                                                              3.73                                                                               106.53                                                                             1.79                                                                               63.80                                                                              .00 .00                                       5   2.500                                                                               7.93                                                                               88.52                                                                              6.18                                                                               86.29                                                                              4.29                                                                               63.15                                                                              2.54                                                                               74.20                                     6   2.000                                                                               10.13                                                                              89.74                                                                              8.43                                                                               88.71                                                                              6.58                                                                               73.81                                                                              4.87                                                                               96.26                                     7   1.700                                                                               12.16                                                                              90.93                                                                              10.50                                                                              90.59                                                                              8.69                                                                               79.78                                                                              7.02                                                                               101.26                                    8   1.500                                                                               14.03                                                                              90.95                                                                              12.40                                                                              90.75                                                                              10.64                                                                              82.18                                                                              9.00                                                                               99.83                                     __________________________________________________________________________     (R,ANGLE) =                                                                             2.500                                                                              -5.229                                                                             2.000                                                                              -6.857                                                                             1.700                                                                              -8.427                                                                             1.500                                                                              -9.960                                    POS R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000     -1.636  -1.627  -1.617  -1.605                                    2   10.000   -1.603  -1.595  -1.587  -1.574                                    3   5.000    -1.561  -1.557  -1.551  -1.540                                    4   3.500    -1.517  -1.522  -1.520  -1.510                                    5   2.500                                                                               -1.487                                                                             .000    -1.496  -1.491  -1.478                                    6   2.000    -1.465                                                                             -1.467                                                                             .000    -1.457  -1.443                                    7   1.700    -1.434  -1.431                                                                             -1.419                                                                             .000    -1.404                                    8   1.500    -1.399  -1.394  -1.381                                                                             -1.367                                                                             .000                                      __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 -8.55                                                                              85.19                                                                              -11.15                                                                             102.51                                                                             -13.63                                                                             97.52                                                                              -15.98                                                                             91.82                                     2   10.000                                                                              -6.55                                                                              83.70                                                                              -9.12                                                                              104.64                                                                             -11.56                                                                             97.92                                                                              -13.88                                                                             91.36                                     3   5.000                                                                               -4.46                                                                              89.01                                                                              -6.99                                                                              113.80                                                                             -9.40                                                                              100.85                                                                             -11.69                                                                             92.02                                     4   3.500                                                                               -2.60                                                                              126.80                                                                             -5.09                                                                              135.16                                                                             -7.46                                                                              105.20                                                                             -9.73                                                                              92.74                                     5   2.500                                                                               .00 .00 -2.44                                                                              125.02                                                                             -4.77                                                                              94.65                                                                              -7.00                                                                              85.55                                     6   2.000                                                                               2.39                                                                               165.94                                                                             .00 .00 -2.29                                                                              84.53                                                                              -4.48                                                                              80.16                                     7   1.700                                                                               4.59                                                                               128.96                                                                             2.25                                                                               91.30                                                                              .00 .00 -2.15                                                                              78.26                                     8   1.500                                                                               6.62                                                                               112.29                                                                             4.32                                                                               86.44                                                                              2.12                                                                               79.64                                                                              .00 .00                                       __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0  = 0.85, K.sub.a      /γ.sub.aR  = 1.17                                                  

                                      TABLE 17                                     __________________________________________________________________________     Conversion Coefficients K.sub.a :(rs), γ.sub.a :(r) Associated with      Direction of Rotation and Correction                                           Coefficient μ: (l) at Telephoto End (196.0 mm) of First Embodiment          f = 196.0 mm                                                                   __________________________________________________________________________     (R,ANGLE) =                                                                             .000                                                                               .000                                                                               10.000                                                                             -1.145                                                                             5.000                                                                              -2.384                                                                             3.500                                                                              -3.529                                    POS R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000 -3.494                                                                             .000    -3.427  -3.360  -3.299                                    2   10.000   -3.473                                                                             -3.409                                                                             .000    -3.345  -3.286                                    3   5.000    -3.455  -3.395                                                                             -3.335                                                                             .000    -3.273                                    4   3.500    -3.440  -3.381  -3.319                                                                             -3.251                                                                             .000                                      5   2.500    -3.405  -3.345  -3.278  -3.206                                    6   2.000    -3.370  -3.309  -3.241  -3.172                                    7   1.700    -3.341  -3.282  -3.216  -3.151                                    8   1.500    -3.298  -3.239  -3.172  -3.106                                    __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 .00 .00 -3.92                                                                              728.18                                                                             -8.01                                                                              1084.28                                                                            -11.64                                                                             792.90                                    2   10.000                                                                              3.97                                                                               640.78                                                                             .00 .00 -4.15                                                                              1365.56                                                                            -7.83                                                                              732.33                                    3   5.000                                                                               8.24                                                                               728.32                                                                             4.21                                                                               1015.44                                                                            .00 .00 -3.75                                                                              547.21                                    4   3.500                                                                               12.14                                                                              778.23                                                                             8.06                                                                               1001.09                                                                            3.80                                                                               804.20                                                                             .00 .00                                       5   2.500                                                                               17.75                                                                              697.08                                                                             13.60                                                                              729.56                                                                             9.27                                                                               538.24                                                                             5.39                                                                               387.69                                    6   2.000                                                                               23.08                                                                              647.35                                                                             18.88                                                                              646.99                                                                             14.47                                                                              514.55                                                                             10.53                                                                              434.44                                    7   1.700                                                                               28.15                                                                              642.61                                                                             23.89                                                                              642.87                                                                             19.43                                                                              543.84                                                                             15.43                                                                              500.18                                    8   1.500                                                                               32.98                                                                              587.96                                                                             28.68                                                                              574.59                                                                             24.16                                                                              493.12                                                                             20.10                                                                              450.45                                    __________________________________________________________________________     (R,ANGLE) =                                                                             2.500                                                                 5.211            2.000                                                                              -6.848                                                                             1.700                                                                              -8.425                                                                             1.500                                                                              -10.000                                   POS R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000     -3.199  -3.101  -3.012  -2.915                                    2   10.000   -3.184  -3.085  -2.998  -2.900                                    3   5.000    -3.166  -3.066  -2.981  -2.881                                    4   3.500    -3.140  -3.043  -2.962  -2.861                                    5   2.500                                                                               -3.098                                                                             .000    -3.013  -2.938  -2.833                                    6   2.000    -3.076                                                                             -3.012                                                                             .000    -2.926  -2.805                                    7   1.700    -3.061  -2.986                                                                             -2.863                                                                             .000    -2.745                                    8   1.500    -3.012  -2.921  -2.810                                                                             -2.727                                                                             .000                                      __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 -16.67                                                                             513.48                                                                             -21.23                                                                             721.32                                                                             -25.38                                                                             486.65                                                                             -29.15                                                                             424.64                                    2   10.000                                                                              -12.95                                                                             467.52                                                                             -17.60                                                                             721.94                                                                             -21.83                                                                             462.66                                                                             -25.68                                                                             406.69                                    3   5.000                                                                               -8.95                                                                              410.07                                                                             -13.69                                                                             755.12                                                                             -18.01                                                                             437.12                                                                             -21.95                                                                             388.61                                    4   3.500                                                                               -5.28                                                                              391.90                                                                             -10.10                                                                             967.85                                                                             -14.50                                                                             421.46                                                                             -18.52                                                                             377.41                                    5   2.500                                                                               .00 .00 -4.93                                                                              20212.1                                                                            -9.44                                                                              361.46                                                                             -13.57                                                                             350.19                                    6   2.000                                                                               5.03                                                                               696.59                                                                             .00 .00 -4.61                                                                              211.10                                                                             -8.84                                                                              310.80                                    7   1.700                                                                               9.84                                                                               829.89                                                                             4.71                                                                               549.97                                                                             .00 .00 -4.32                                                                              689.10                                    8   1.500                                                                               14.42                                                                              521.36                                                                             9.21                                                                               306.54                                                                             4.41                                                                               202.05                                                                             .00 .00                                       __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0  = 0.94, K.sub.a      /γ.sub.aR  = 1.07                                                  

As can be seen from Tables 15, 16, and 17 above, when a change in conversion coefficient K_(a) : (rs) (e.g., the fourth column in the first table) at a given lens arrangement (e.g., at the infinity in-focus arrangement) is considered, the rate of change becomes small as compared to the change in K_(a) (Tables 6, 7, and 8) in the embodiment of,Japanese Patent Application Laid-Open No. 5-142475 examined previously.

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end (F=81.5), middle position (F=135.0), and telephoto end (F=196.0) in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the first embodiment of the present invention are as follows.

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement                                                                       Closest Arrangement                                                K.sub.aO /γ.sub.aO                                                                   K.sub.aK /γ.sub.aK                                  ______________________________________                                         Wide-angle End                                                                            2.75          0.44                                                  (F = 36.0)                                                                     Middle Position                                                                           3.36          0.43                                                  (F = 50.0)                                                                     Telephoto End                                                                             3.80          0.43                                                  (F = 103.0)                                                                    First Embodiment                                                               Wide-angle End                                                                            0.84          1.25                                                  (F = 81.5)                                                                     Middle Position                                                                           0.85          1.17                                                  (F = 135.0)                                                                    Telephoto End                                                                             0.94          1.07                                                  (F = 196.0)                                                                    ______________________________________                                    

As described above, according to the present invention, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, and the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced, the value of the correction coefficient μ can be set to be large as compared to the defocus amount ΔBf, and at the same time, the change in correction coefficient μ can be decreased.

Therefore, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error in the conversion coefficient K_(a) calculated using γ_(a) and μ or in the actual lens driving amount Δa for focusing can be eliminated.

Next, in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the first embodiment of the present invention, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end (F=81.5), middle position (F=135.0), and telephoto end (F=196.0) are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                            -4.4%          -13.0%                                               (F = 36.0)                                                                     Middle Position                                                                           -11.8%         -12.0%                                               (F = 50.0)                                                                     Telephoto End                                                                             -12.6%         -14.6%                                               (F = 103.0)                                                                    First Embodiment                                                               Wide-angle End                                                                            -2.1%          -1.4%                                                (F = 81.5)                                                                     Middle Position                                                                           0.1%           -0.3%                                                (F = 135.0)                                                                    Telephoto End                                                                             -0.9%          -0.8%                                                (F = 196.0)                                                                    ______________________________________                                    

As described above, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Next, an examination will be made as to whether not only accurate auto-focusing but also so-called manual focusing can be attained in the zoom lens of the first embodiment.

Table 18 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 10) of the first embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

The upper table in Table 18 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m) in the respective zooming states of the focal lengths (F=81.5, 105.0, 135.0, 150.0, and 196.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances (R=5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m). Note that the amounts of rotation for focusing, which have values for eliminating any displacement of the imaging point at the wide-angle end and the telephoto end, are selected. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the photographing distances (R=5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m) in the respective zooming states with the focal lengths (F=81.5, 105.0, 135.0, 150.0, and 196.0 mm). In the lower table, (F) is the focal length (mm) of the entire system, (R) is the photographing distance (m), and (DX) is the amount (mm) of movement, in the direction of the optical axis, of each of the first, second, third, and fourth lens units in turn from the right side. Note that the amount of movement in the direction of the optical axis toward the object side is represented by a positive value.

                                      TABLE 18                                     __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in First Embodiment                                      1.50 m                                                                              1.70 m                                                                              2.00 m                                                                              2.50 m                                                                              3.50 m                                                                              5.00 m                                        __________________________________________________________________________     F 81.500 Bf                                                                            .000 .000 .000 .000 .000 .000                                          F 105.000 Bf                                                                           -.039                                                                               .005 -.001                                                                               .013 .029 .024                                          F 135.000 Bf                                                                           -.055                                                                               .003 .013 .026 -.020                                                                               -.022                                         F 150.000 Bf                                                                           -.055                                                                               .027 .023 -.019                                                                               -.013                                                                               -.012                                         F 196.000 Bf                                                                           .000 .000 .000 .000 .000 .000                                            ANGLE DA                                                                             -10.000                                                                             -8.425                                                                              -6.848                                                                              -5.211                                                                              -3.529                                                                              -2.384                                        F 81.500 DX                                                                            .000 -13.544                                                                             .000 .000 R                                                                              1.50 m                                             F 105.000 DX                                                                           .000 -13.914                                                                             .000 .000 R                                                                              1.50 m                                             F 135.000 DX                                                                           .000 -14.468                                                                             .000 .000 R                                                                              1.50 m                                             F 150.000 DX                                                                           .000 -14.736                                                                             .000 .000 R                                                                              1.50 m                                             F 196.000 DX                                                                           .000 -15.450                                                                             .000 .000 R                                                                              1.50 m                                             F 81.500 DX                                                                            .000 -11.572                                                                             .000 .000 R                                                                              1.70 m                                             F 105.000 DX                                                                           .000 -11.828                                                                             .000 .000 R                                                                              1.70 m                                             F 135.000 DX                                                                           .000 -12.308                                                                             .000 .000 R                                                                              1.70 m                                             F 150.000 DX                                                                           .000 -12.524                                                                             .000 .000 R                                                                              1.70 m                                             F 196.000 DX                                                                           .000 -13.187                                                                             .000 .000 R                                                                              1.70 m                                             F 81.500 DX                                                                            .000 -9.497                                                                              .000 .000 R                                                                              2.00 m                                             F 105.000 DX                                                                           .000 -9.715                                                                              .000 .000 R                                                                              2.00 m                                             F 135.000 DX                                                                           .000 -10.088                                                                             .000 .000 R                                                                              2.00 m                                             F 150.000 DX                                                                           .000 -10.273                                                                             .000 .000 R                                                                              2.00 m                                             F 196.000 DX                                                                           .000 -10.812                                                                             .000 .000 R                                                                              2.00 m                                             F 81.500 DX                                                                            .000 -7.312                                                                              .000 .000 R                                                                              2.50 m                                             F 105.000 DX                                                                           .000 -7.459                                                                              .000 .000 R                                                                              2.50 m                                             F 135.000 DX                                                                           .000 -7.750                                                                              .000 .000 R                                                                              2.50 m                                             F 150.000 DX                                                                           .000 -7.936                                                                              .000 .000 R                                                                              2.50 m                                             F 196.000 DX                                                                           .000 -8.316                                                                              .000 .000 R                                                                              2.50 m                                             F 81.500 DX                                                                            .000 -5.008                                                                              .000 .000 R                                                                              3.50 m                                             F 105.000 DX                                                                           .000 -5.078                                                                              .000 .000 R                                                                              3.50 m                                             F 135.000 DX                                                                           .000 -5.342                                                                              .000 .000 R                                                                              3.50 m                                             F 150.000 DX                                                                           .000 -5.432                                                                              .000 .000 R                                                                              3.50 m                                             F 196.000 DX                                                                           .000 -5.689                                                                              .000 .000 R                                                                              3.50 m                                             F 81.500 DX                                                                            .000 -3.401                                                                              .000 .000 R                                                                              5.00 m                                             F 105.000 DX                                                                           .000 -3.441                                                                              .000 .000 R                                                                              5.00 m                                             F 135.000 DX                                                                           .000 -3.634                                                                              .000 .000 R                                                                              5.00 m                                             F 150.000 DX                                                                           .000 -3.690                                                                              .000 .000 R                                                                              5.00 m                                             F 196.000 DX                                                                           .000 -3.860                                                                              .000 .000 R                                                                              5.00 m                                             __________________________________________________________________________

As can be seen from Table 18, so-called manual focusing can be attained since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

Second Embodiment!

The second embodiment is directed to a zoom lens which has a five-unit arrangement, i.e., positive, negative, negative, positive and negative lens units, and attains focusing by a negative second lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=1.8 m) to the amount of rotation for zooming from the wide-angle end (F=103.0) to the telephoto end (F=292.0) is set to be -0.50.

Table 19 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the second embodiment.

The upper table in Table 19 summarizes the focal lengths and principal point interval data of the respective lens units of the optical system corresponding to the second embodiment in association with five zooming states (focal length F=103.0 (1-POS), 150.0 (2-POS), 200.0 (3-POS), 250.0 (4-POS), and 292.0 mm (5-POS)).

The middle table in Table 19 summarizes spline sample data when the shape of the focus cam in the second lens unit of the second embodiment, which is used for focusing, is expressed by the above-mentioned spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), (4), and (5) correspond to the first, second, third, fourth, and fifth lens units, respectively.

Furthermore, the lower table in Table 19 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (focal length F=103.0, 150.0, 200.0, 250.0, and 292.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=10.0, 5.0, 3.5, 2.5, 2.0, and 1.8 m) using the focus cam of the second embodiment. In this table, since the amount of rotation for zooming from the wide-angle end (F=103.0) to the telephoto end (F=292.0) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=1.8 m) is set to be -5.0, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the second embodiment is -0.50.

                                      TABLE 19                                     __________________________________________________________________________     Second Embodiment f = 103.0 to 292.0                                           (Rotation Amount Ratio: a.sub.F /a.sub.Z = -0.50)                              Focal lengths and Principal Point Intervals of                                 Lens Units of Second Embodiment                                                          1-POS                                                                               2-POS                                                                               3-POS                                                                               4-POS                                                                               5-POS                                            __________________________________________________________________________             F 103.0000                                                                            150.0000                                                                            200.0000                                                                            250.0000                                                                            292.0000                                         F1 127.0000                                                                            D1                                                                               10.0001                                                                             25.7666                                                                             39.7534                                                                             52.4332                                                                             62.0982                                          F2 -130.0000                                                                           D2                                                                               15.5000                                                                             17.9256                                                                             18.6504                                                                             18.3740                                                                             18.0209                                          F3 -115.0000                                                                           D3                                                                               42.3450                                                                             28.6860                                                                             20.1672                                                                             15.2868                                                                             12.8809                                          F4 46.0000                                                                             D4                                                                               38.3430                                                                             33.8099                                                                             27.6171                                                                             20.0942                                                                             13.1881                                          F5 -50.0000                                                                            D5                                                                               48.8620                                                                             60.9901                                                                             72.1979                                                                             82.6732                                                                             90.8766                                          __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point)                            Corresponding to Second Embodiment                                                 ANGLE                                                                               (1)  (2)  (3)  (4)  (5)                                               __________________________________________________________________________      1  -10.0000                                                                            .0000                                                                               -19.5000                                                                            .0000                                                                               .0000                                                                               .0000                                              2  -5.0000                                                                             .0000                                                                               -10.7337                                                                            .0000                                                                               .0000                                                                               .0000                                              3  -4.3573                                                                             .0000                                                                               -9.4841                                                                             .0000                                                                               .0000                                                                               .0000                                              4  -3.3008                                                                             .0000                                                                               -7.3459                                                                             .0000                                                                               .0000                                                                               .0000                                              5  -2.2248                                                                             .0000                                                                               -5.0630                                                                             .0000                                                                               .0000                                                                               .0000                                              6  -1.4951                                                                             .0000                                                                               -3.4533                                                                             .0000                                                                               .0000                                                                               .0000                                              7  -.7148                                                                              .0000                                                                               -1.6765                                                                             .0000                                                                               .0000                                                                               .0000                                              8  .0000                                                                               .0000                                                                               .0000                                                                               .0000                                                                               .0000                                                                               .0000                                              9  5.0000                                                                              .0000                                                                               12.8713                                                                             .0000                                                                               .0000                                                                               .0000                                             10  5.6427                                                                              .0000                                                                               14.6829                                                                             .0000                                                                               .0000                                                                               .0000                                             11  6.6992                                                                              .0000                                                                               17.7317                                                                             .0000                                                                               .0000                                                                               .0000                                             12  7.7752                                                                              .0000                                                                               20.9197                                                                             .0000                                                                               .0000                                                                               .0000                                             13  8.5049                                                                              .0000                                                                               23.1279                                                                             .0000                                                                               .0000                                                                               .0000                                             14  9.2852                                                                              .0000                                                                               25.5286                                                                             .0000                                                                               .0000                                                                               .0000                                             15  10.0000                                                                             .0000                                                                               27.7598                                                                             .0000                                                                               .0000                                                                               .0000                                             16  11.0000                                                                             .0000                                                                               30.9000                                                                             .0000                                                                               .0000                                                                               .0000                                             __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation                          for Focusing of Second Embodiment                                              (Rotation Amount Ratio: a.sub.F /a.sub.Z = -0.50)                                     Infinity          Amount of                                                    Correspond-                                                                             Photograph-                                                                             Rotation for                                          Focal Length                                                                          ing Position                                                                            ing Distance                                                                            Focusing                                              __________________________________________________________________________     103.0 mm                                                                              .0000    10.00 m  -.715                                                 150.0 mm                                                                              1.2300   5.00 m   -1.495                                                200.0 mm                                                                              3.2800   3.50 m   -2.225                                                250.0 mm                                                                              6.2600   2.50 m   -3.301                                                292.0 mm                                                                              10.0000  2.00 m   -4.357                                                                1.80 m   -5.000                                                __________________________________________________________________________     Condition Corresponding Value (1)                                                             0.98 (wide-angle end)                                                                    0.85 (telephoto end)                                  Condition Corresponding Value (2)                                                             1.39                                                            Condition Corresponding Value (3)                                                             0.50                                                            Condition Corresponding Value (4)                                                             0.79 (wide-angle end)                                                                    0.76 (telephoto end)                                  Condition Corresponding Value (5)                                                             0.88 (wide-angle end)                                                                    1.33 (telephoto end)                                  Condition Corresponding Value (6)                                                             1.15 (wide-angle end)                                                                    0.85 (telephoto end)                                  __________________________________________________________________________

Table 20 below summarizes the numerical value data of the cams of the focusing lens unit in the second embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 19. Note that the meanings of the reference symbols in Table 20 are the same as those in the first embodiment.

                  TABLE 20                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit in Second Embodiment                                  Zoom Compensation Cam                                    Focus Cam Numerical Value Data                                                                       Numerical Value Data                                     ANGLE  (2)      F         ANGLE  (2)    F                                      ______________________________________                                         -5.0000                                                                               -10.7337 .0000                                                          -4.5000                                                                               -9.7649  .0000                                                          -4.0000                                                                               -8.7724  .0000                                                          -3.5000                                                                               -7.7568  .0000                                                          -3.0000                                                                               -6.7185  .0000                                                          -2.5000                                                                               -5.6572  .0000                                                          -2.0000                                                                               -4.5724  .0000                                                          -1.5000                                                                               -3.4641  .0000                                                          -1.0000                                                                               -2.3326  .0000                                                          .5000  -1.1773  .0000                                                          .0000  .0000    103.0000  .0000  .0000  103.0000                               .5000  1.1964   123.8480  .5000  -2.9748                                                                               123.8480                               1.0000 2.4117   142.5575  1.0000 -5.5571                                                                               142.5575                               1.5000 3.6464   157.9248  1.5000 -7.7814                                                                               157.9248                               2.0000 4.9008   171.0716  2.0000 -9.8046                                                                               171.0716                               2.5000 6.1756   182.9606  2.5000 -11.7266                                                                              182.9606                               3.0000 7.4712   194.0439  3.0000 -13.5927                                                                              194.0439                               3.5000 8.7881   204.5715  3.5000 -15.4280                                                                              204.5715                               4.0000 10.1267  214.5013  4.0000 -17.2365                                                                              214.5013                               4.5000 11.4876  223.6523  4.5000 -19.0132                                                                              223.6523                               5.0000 12.8713  232.0037  5.0000 -20.7611                                                                              232.0037                               5.5000 14.2777  239.6199  5.5000 -22.4864                                                                              239.6199                               6.0000 15.7047  246.5950  6.0000 -24.1938                                                                              246.5950                               6.5000 17.1507  253.0244  6.5000 -25.8881                                                                              253.0244                               7.0000 18.6147  259.0424  7.0000 -27.5762                                                                              259.0424                               7.5000 20.0965  264.7876  7.5000 -29.2650                                                                              264.7876                               8.0000 21.5961  270.3530  8.0000 -30.9598                                                                              270.3530                               8.5000 23.1131  275.8068  8.5000 -32.6633                                                                              275.8068                               9.0000 24.6464  281.2024  9.0000 -34.3775                                                                              281.2024                               9.5000 26.1965  286.5859  9.5000 -36.1047                                                                              286.5859                               10.0000                                                                               27.7598  292.0000  10.0000                                                                               -37.8433                                                                              292.0000                               ______________________________________                                    

The left table in Table 20 summarizes the numerical value data of the focus cam of the second embodiment, and the right table in Table 20 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amounts (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) coincides with the movement locus of the second lens unit calculated using the paraxial data in the upper table in Table 19.

Tables 21, 22, and 23 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(x) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F =103.0), the middle position (F=200.0), and the telephoto end (F=292.0) according to the second embodiment, respectively. The arrangements of the respective tables and the meanings of the reference symbols are the same as those in the first embodiment.

                                      TABLE 21                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical                Axis at Wide-angle End (103.0 mm) in Second Embodiment                         __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .000                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -.715                                                                              1) .000                                                                             2) -1.677                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -1.495                                                                             1) .000                                                                             2) -3.453                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               -1.913                                                                             1) .000                                                                             2) -4.382                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               -2.658                                                                             1) .000                                                                             2) -5.994                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -3.301                                                                             1) .000                                                                             2) -7.346                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -4.357                                                                             1) .000                                                                             2) -9.484                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               -5.000                                                                             1) .000                                                                             2) -10.734                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Wide-angle                 End (103.0 mm) in Second Embodiment                                            __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 10.000                                                                            3) -.111                                                                            4) -.371                                                                            5) 1.977                                     R 10.000                                                                             ANG                                                                               -.715                                                                              1) -.013                                                                            2) 9.987                                                                             3) -.111                                                                            4) -.371                                                                            5) 1.977                                     R 5.000                                                                              ANG                                                                               -1.495                                                                             1) -.027                                                                            2) 9.973                                                                             3) -.111                                                                            4) -.371                                                                            5) 1.977                                     R 4.000                                                                              ANG                                                                               -1.913                                                                             1) -.034                                                                            2) 9.966                                                                             3) -.111                                                                            4) -.371                                                                            5) 1.977                                     R 3.000                                                                              ANG                                                                               -2.658                                                                             1) -.047                                                                            2) 9.954                                                                             3) -.111                                                                            4) -.371                                                                            5) 1.977                                     R 2.500                                                                              ANG                                                                               -3.301                                                                             1) -.057                                                                            2) 9.943                                                                             3) -.111                                                                            4) -.371                                                                            5) 1.977                                     R 2.000                                                                              ANG                                                                               -4.357                                                                             1) -.074                                                                            2) 9.927                                                                             3) -.111                                                                            4) -.371                                                                            5) 1.977                                     R 1.800                                                                              ANG                                                                               -5.000                                                                             1) -.084                                                                            2) 9.917                                                                             3) -.111                                                                            4) -.371                                                                            5) 1.977                                     __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction                 of Optical Axis at Wide-angle End (103.0 mm) in Second Embodiment              __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -.651                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -.715                                                                              1) .000                                                                             2) -.649                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -1.495                                                                             1) .000                                                                             2) -.648                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               -1.913                                                                             1) .000                                                                             2) -.647                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               -2.658                                                                             1) .000                                                                             2) -.645                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -3.301                                                                             1) .000                                                                             2) -.644                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -4.357                                                                             1) .000                                                                             2) -.642                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               -5.000                                                                             1) .000                                                                             2) -.640                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Wide-angle End (103.0 mm)                          in Second Embodiment                                                           __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 2.374                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -.715                                                                              1) .000                                                                             2) 2.314                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -1.495                                                                             1) .000                                                                             2) 2.240                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               -1.913                                                                             1) .000                                                                             2) 2.201                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               -2.658                                                                             1) .000                                                                             2) 2.131                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -3.301                                                                             1) .000                                                                             2) 2.072                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -4.357                                                                             1) .000                                                                             2) 1.975                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               -5.000                                                                             1) .000                                                                             2) 1.914                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction                 of Rotation at Wide-angle End (103.0 mm) in Second Embodiment                  __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -1.546                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -.715                                                                              1) .000                                                                             2) -1.503                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -1.495                                                                             1) .000                                                                             2) -1.451                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               -1.913                                                                             1) .000                                                                             2) -1.424                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               -2.658                                                                             1) .000                                                                             2) -1.375                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -3.301                                                                             1) .000                                                                             2) -1.334                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -4.357                                                                             1) .000                                                                             2) -1.267                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               -5.000                                                                             1) .000                                                                             2) -1.226                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 0.98,         γ.sub.aR /γ.sub.aO = 0.79                                    

                                      TABLE 22                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical                Axis at Middle Position (200.0 mm) in Second Embodiment                        __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .000                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -.716                                                                              1) .000                                                                             2) -1.867                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -1.499                                                                             1) .000                                                                             2) -3.857                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               -1.918                                                                             1) .000                                                                             2) -4.902                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               -2.663                                                                             1) .000                                                                             2) -6.726                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -3.304                                                                             1) .000                                                                             2) -8.262                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -4.354                                                                             1) .000                                                                             2) -10.708                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               -4.994                                                                             1) .000                                                                             2) -12.147                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Middle Position            (200.0 mm) in Second Embodiment                                                __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 3.041                                                                             3) -.874                                                                            4) -.243                                                                            5) 2.444                                     R 10.000                                                                             ANG                                                                               -.716                                                                              1) -.013                                                                            2) 3.026                                                                             3) -.874                                                                            4) -.243                                                                            5) 2.444                                     R 5.000                                                                              ANG                                                                               -1.499                                                                             1) -.027                                                                            2) 3.011                                                                             3) -.874                                                                            4) -.243                                                                            5) 2.444                                     R 4.000                                                                              ANG                                                                               -1.918                                                                             1) -.034                                                                            2) 3.003                                                                             3) -.874                                                                            4) -.243                                                                            5) 2.444                                     R 3.000                                                                              ANG                                                                               -2.663                                                                             1) -.047                                                                            2) 2.989                                                                             3) -.874                                                                            4) -.243                                                                            5) 2.444                                     R 2.500                                                                              ANG                                                                               -3.304                                                                             1) -.058                                                                            2) 2.977                                                                             3) -.874                                                                            4) -.243                                                                            5) 2.444                                     R 2.000                                                                              ANG                                                                               -4.354                                                                             1) -.075                                                                            2) 2.958                                                                             3) -.874                                                                            4) -.243                                                                            5) 2.444                                     R 1.800                                                                              ANG                                                                               -4.994                                                                             1) -.085                                                                            2) 2.947                                                                             3) -.874                                                                            4) -.243                                                                            5) 2.444                                     __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction                 of Optical Axis at Middle Position (200.0 mm) in Second                        __________________________________________________________________________     Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -2.212                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -.716                                                                              1) .000                                                                             2) -2.188                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -1.499                                                                             1) .000                                                                             2) -2.164                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               -1.918                                                                             1) .000                                                                             2) -2.151                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               -2.663                                                                             1) .000                                                                             2) -2.128                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -3.304                                                                             1) .000                                                                             2) -2.109                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -4.354                                                                             1) .000                                                                             2) -2.079                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               -4.994                                                                             1) .000                                                                             2) -2.062                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Middle Position (200.0 mm)                         in Second Embodiment                                                           __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 2.636                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -.716                                                                              1) .000                                                                             2) 2.576                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -1.499                                                                             1) .000                                                                             2) 2.511                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               -1.918                                                                             1) .000                                                                             2) 2.478                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               -2.663                                                                             1) .000                                                                             2) 2.420                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -3.304                                                                             1) .000                                                                             2) 2.373                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -4.354                                                                             1) .000                                                                             2) 2.280                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               -4.994                                                                             1) .000                                                                             2) 2.220                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction                 of Rotation at Middle Position (200.0 mm) in Second Embodiment                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -5.831                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               -.716                                                                              1) .000                                                                             2) -5.636                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               -1.499                                                                             1) .000                                                                             2) -5.434                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               -1.918                                                                             1) .000                                                                             2) -5.329                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               -2.663                                                                             1) .000                                                                             2) -5.151                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               -3.304                                                                             1) .000                                                                             2) -5.004                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               -4.354                                                                             1) .000                                                                             2) -4.740                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               -4.994                                                                             1) .000                                                                             2) -4.577                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 0.93,         γ.sub.aR /γ.sub.aO = 0.78                                    

                                      TABLE 23                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical                Axis at Telephoto End (292.0 mm) in Second Embodiment                          __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .000                                                                              3) .000                                                                              4) .000                                                                             5) .000                                     R 10.000                                                                             ANG                                                                               -.715                                                                              1) .000                                                                             2) -2.231                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 5.000                                                                              ANG                                                                               -1.495                                                                             1) .000                                                                             2) -4.632                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 4.000                                                                              ANG                                                                               -1.913                                                                             1) .000                                                                             2) -5.902                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 3.000                                                                              ANG                                                                               -2.658                                                                             1) .000                                                                             2) -8.133                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 2.500                                                                              ANG                                                                               -3.301                                                                             1) .000                                                                             2) -10.028                                                                           3) .000                                                                              4) .000                                                                             5) .000                                     R 2.000                                                                              ANG                                                                               -4.357                                                                             1) .000                                                                             2) -13.077                                                                           3) .000                                                                              4) .000                                                                             5) .000                                     R 1.800                                                                              ANG                                                                               -5.000                                                                             1) .000                                                                             2) -14.889                                                                           3) .000                                                                              4) .000                                                                             5) .000                                     __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Telephoto End              (292.0 mm) in Second Embodiment                                                __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 1.997                                                                             3) 33.692                                                                            4) .012                                                                             5) 2.818                                    R 10.000                                                                             ANG                                                                               -.715                                                                              1) -.013                                                                            2) 1.980                                                                             3) 33.692                                                                            4) .012                                                                             5) 2.818                                    R 5.000                                                                              ANG                                                                               -1.495                                                                             1) -.027                                                                            2) 1.961                                                                             3) 33.692                                                                            4) .012                                                                             5) 2.818                                    R 4.000                                                                              ANG                                                                               -1.913                                                                             1) -.035                                                                            2) 1.952                                                                             3) 33.692                                                                            4) .012                                                                             5) 2.818                                    R 3.000                                                                              ANG                                                                               -2.658                                                                             1) -.047                                                                            2) 1.934                                                                             3) 33.692                                                                            4) .012                                                                             5) 2.818                                    R 2.500                                                                              ANG                                                                               -3.301                                                                             1) -.058                                                                            2) 1.920                                                                             3) 33.692                                                                            4) .012                                                                             5) 2.818                                    R 2.000                                                                              ANG                                                                               -4.357                                                                             1) -.076                                                                            2) 1.896                                                                             3) 33.692                                                                            4) .012                                                                             5) 2.818                                    R 1.800                                                                              ANG                                                                               -5.000                                                                             1) -.086                                                                            2) 1.882                                                                             3) 33.692                                                                            4) .012                                                                             5) 2.818                                    __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction                 of Optical Axis at Telephoto End (292.0 mm) in Second Embodiment               __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -3.961                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 10.000                                                                             ANG                                                                               -.715                                                                              1) .000                                                                             2) -3.870                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 5.000                                                                              ANG                                                                               -1.495                                                                             1) .000                                                                             2) -3.774                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 4.000                                                                              ANG                                                                               -1.913                                                                             1) .000                                                                             2) -3.723                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 3.000                                                                              ANG                                                                               -2.658                                                                             1) .000                                                                             2) -3.635                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 2.500                                                                              ANG                                                                               -3.301                                                                             1) .000                                                                             2) -3.560                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 2.000                                                                              ANG                                                                               -4.357                                                                             1) .000                                                                             2) -3.442                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 1.800                                                                              ANG                                                                               -5.000                                                                             1) .000                                                                             2) -3.372                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     __________________________________________________________________________     Slope dx/da of Focus Cam at Telephoto End (292.0 mm)                           in Second Embodiment                                                           __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 3.134                                                                             3) .000                                                                              4) .000                                                                             5) .000                                     R 10.000                                                                             ANG                                                                               -.715                                                                              1) .000                                                                             2) 3.103                                                                             3) .000                                                                              4) .000                                                                             5) .000                                     R 5.000                                                                              ANG                                                                               -1.495                                                                             1) .000                                                                             2) 3.051                                                                             3) .000                                                                              4) .000                                                                             5) .000                                     R 4.000                                                                              ANG                                                                               -1.913                                                                             1) .000                                                                             2) 3.023                                                                             3) .000                                                                              4) .000                                                                             5) .000                                     R 3.000                                                                              ANG                                                                               -2.658                                                                             1) .000                                                                             2) 2.970                                                                             3) .000                                                                              4) .000                                                                             5) .000                                     R 2.500                                                                              ANG                                                                               -3.301                                                                             1) .000                                                                             2) 2.924                                                                             3) .000                                                                              4) .000                                                                             5) .000                                     R 2.000                                                                              ANG                                                                               -4.357                                                                             1) .000                                                                             2) 2.846                                                                             3) .000                                                                              4) .000                                                                             5) .000                                     R 1.800                                                                              ANG                                                                               -5.000                                                                             1) .000                                                                             2) 2.790                                                                             3) .000                                                                              4) .000                                                                             5) .000                                     __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction                 of Rotation at Telephoto End (292.0 mm) in Second Embodiment                   __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -12.414                                                                           3) .000                                                                              4) .000                                                                             5) .000                                     R 10.000                                                                             ANG                                                                               -.715                                                                              1) .000                                                                             2) -12.009                                                                           3) .000                                                                              4) .000                                                                             5) .000                                     R 5.000                                                                              ANG                                                                               -1.495                                                                             1) .000                                                                             2) -11.513                                                                           3) .000                                                                              4) .000                                                                             5) .000                                     R 4.000                                                                              ANG                                                                               -1.913                                                                             1) .000                                                                             2) -11.255                                                                           3) .000                                                                              4) .000                                                                             5) .000                                     R 3.000                                                                              ANG                                                                               -2.658                                                                             1) .000                                                                             2) -10.796                                                                           3) .000                                                                              4) .000                                                                             5) .000                                     R 2.500                                                                              ANG                                                                               -3.301                                                                             1) .000                                                                             2) -10.412                                                                           3) .000                                                                              4) .000                                                                             5) .000                                     R 2.000                                                                              ANG                                                                               -4.357                                                                             1) .000                                                                             2) -9.794                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     R 1.800                                                                              ANG                                                                               -5.000                                                                             1) .000                                                                             2) -9.409                                                                            3) .000                                                                              4) .000                                                                             5) .000                                     __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 0.85,         γ.sub.aR /γ.sub.aO = 0.76                                    

As can be seen from Tables 21, 22, and 23, at each focal length, the value of the conversion coefficient γ_(x) associated with the direction of the optical axis, and the value of the slope (dx/da) of the focus cam decreases as the photographing distance becomes closer to the closest distance. However, since the degree of the changes is small in any case, the width of changes in the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, becomes small.

From Tables 21, 22, and 23, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×0.79 at the wide-angle end (F=103.0), ×0.78 at the middle position (F=200.0), and ×0.76 at the telephoto end (F =292.0). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the second embodiment is calculated using formula (a), and is compared with that in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values:

Embodiment of Japanese Patent Application

Laid-Open No. 5-142475

    N.sub.W >9.3 N.sub.M >10.1 N.sub.T >8.1

Second Embodiment

    N.sub.W >1.3 N.sub.M >1.3 N.sub.T >1.5

Therefore, as can be seen from a comparison with the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the values of the numbers N of divisions become very small.

As described above, in the second embodiment as well, since the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation is much smaller than that in the conventional system so that the number of data of the conversion coefficient γ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Tables 24, 25, and 26 summarize the calculation results of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=103.0), middle position (F=200.0), and telephoto end (F=292.0) according to the second embodiment. The arrangements of the tables and reference symbols are the same as those in the first embodiment. The position of the focusing lens in the first pair in the upper two tables in each of Tables 24, 25, and 26, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 24, 25, and 26, i.e., in the ninth and tenth columns is (R, ANGLE)=(1.8, -5.0), and it indicates that this position corresponds to the closest in-focus (R=1.8 m) corresponding position.

                                      TABLE 24                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of                                                              Rotation and Correction Coefficient μ: (l) at Wide-angle End                (103.0 mm) of Second Embodiment                                                f = 103.0 mm                                                                   (R,ANGLE) =                                                                            .000                                                                               .000                                                                               10.000                                                                             -.715                                                                              5.000                                                                              -1.495                                                                             4.000                                                                              -1.913                                     POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000                                                                               -1.546                                                                             .000    -1.530  -1.509  -1.497                                     2   10.000  -1.520                                                                             -1.503                                                                             .000    -1.481  -1.470                                     3   5.000   -1.490  -1.472                                                                             -1.451                                                                             .000    -1.440                                     4   4.000   -1.474  -1.456  -1.435                                                                             -1.424                                                                             .000                                       5   3.000   -1.445  -1.427  -1.407  -1.395                                     6   2.500   -1.421  -1.403  -1.383  -1.372                                     7   2.000   -1.381  -1.364  -1.344  -1.333                                     8   1.800   -1.358  -1.341  -1.321  -1.310                                     __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               .00 .00 -1.09                                                                              59.92                                                                              -2.26                                                                              56.30                                                                              -2.87                                                                              55.24                                      2   10.000                                                                             1.09                                                                               64.88                                                                              .00 .00 -1.16                                                                              55.07                                                                              -1.76                                                                              54.27                                      3   5.000                                                                              2.23                                                                               61.21                                                                              1.15                                                                               56.09                                                                              .00 .00 -.60                                                                               53.17                                      4   4.000                                                                              2.82                                                                               60.14                                                                              1.74                                                                               55.86                                                                              .60 54.81                                                                              .00 .00                                        5   3.000                                                                              3.84                                                                               58.69                                                                              2.77                                                                               55.20                                                                              1.64                                                                               53.64                                                                              1.04                                                                               52.49                                      6   2.500                                                                              4.69                                                                               57.74                                                                              3.63                                                                               54.66                                                                              2.50                                                                               53.08                                                                              1.90                                                                               52.08                                      7   2.000                                                                              6.02                                                                               56.50                                                                              4.97                                                                               53.87                                                                              3.85                                                                               52.33                                                                              3.26                                                                               51.44                                      8   1.800                                                                              6.79                                                                               55.79                                                                              5.75                                                                               53.33                                                                              4.63                                                                               51.76                                                                              4.04                                                                               50.87                                      __________________________________________________________________________     (R,ANGLE) =                                                                            3.000                                                                              -2.658                                                                             2.500                                                                              -3.301                                                                             2.000                                                                              -4.357                                                                             1.800                                                                              -5.000                                     POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000    -1.476  -1.457  -1.426  -1.406                                     2   10.000  -1.449  -1.430  -1.399  -1.379                                     3   5.000   -1.419  -1.400  -1.370  -1.351                                     4   4.000   -1.403  -1.385  -1.354  -1.335                                     5   3.000                                                                              -1.374                                                                             .000    -1.357  -1.327  -1.309                                     6   2.500   -1.351                                                                             -1.334                                                                             .000    -1.304  -1.286                                     7   2.000   -1.314  -1.297                                                                             -1.267                                                                             .000    -1.248                                     8   1.800   -1.291  -1.274  -1.244                                                                             -1.226                                                                             .000                                       __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               -3.92                                                                              53.10                                                                              -4.81                                                                              52.17                                                                              -6.21                                                                              49.50                                                                              -7.03                                                                              47.98                                      2   10.000                                                                             -2.81                                                                              52.22                                                                              -3.70                                                                              51.53                                                                              -5.09                                                                              48.85                                                                              -5.91                                                                              47.35                                      3   5.000                                                                              -1.65                                                                              51.27                                                                              -2.53                                                                              50.99                                                                              -3.92                                                                              48.19                                                                              -4.73                                                                              46.71                                      4   4.000                                                                              -1.04                                                                              50.66                                                                              -1.92                                                                              50.81                                                                              -3.31                                                                              47.83                                                                              -4.12                                                                              46.36                                      5   3.000                                                                              .00 .00 -.87                                                                               50.75                                                                              -2.26                                                                              47.08                                                                              -3.06                                                                              45.69                                      6   2.500                                                                              .87 51.80                                                                              .00 .00 -1.38                                                                              46.10                                                                              -2.18                                                                              45.03                                      7   2.000                                                                              2.23                                                                               50.53                                                                              1.37                                                                               48.63                                                                              .00 .00 -.80                                                                               44.38                                      8   1.800                                                                              3.02                                                                               49.72                                                                              2.16                                                                               47.82                                                                              .80 45.38                                                                              .00 .00                                        __________________________________________________________________________      Condition Corresponding Values: K.sub.aO /γ.sub.aO = 0.88, K.sub.aR      /γ.sub.aR = 1.15                                                   

                                      TABLE 25                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of                                                              Rotation and Correction Coefficient μ: (l) at Middle Position               (200.0 mm) of Second Embodiment                                                f = 200.0 mm                                                                   (R,ANGLE) =                                                                            .000                                                                               .000                                                                               10.000                                                                             -.716                                                                              5.000                                                                              -1.499                                                                             4.000                                                                              -1.918                                     POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000                                                                               -5.830                                                                             .000    -5.606  -5.377  -5.260                                     2   10.000  -5.864                                                                             -5.635                                                                             .000    -5.404  -5.286                                     3   5.000   -5.901  -5.670                                                                             -5.435                                                                             .000    -5.314                                     4   4.000   -5.920  -5.687  -5.450                                                                             -5.328                                                                             .000                                       5   3.000   -5.995  -5.719  -5.479  -5.357                                     6   2.500   -5.986  -5.747  -5.504  -5.381                                     7   2.000   -6.033  -5.789  -5.540  -5.413                                     8   1.800   -6.056  -5.808  -5.555  -5.426                                     __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               .00 .00 -4.02                                                                              -789.53                                                                            -8.06                                                                              -753.14                                                                            -10.09                                                                             -787.33                                    2   10.000                                                                             4.20                                                                               -729.77                                                                            .00 .00 -4.23                                                                              -748.10                                                                            -6.35                                                                              -798.21                                    3   5.000                                                                              8.84                                                                               -731.58                                                                            4.44                                                                               -720.90                                                                            .00 .00 -2.23                                                                              -809.86                                    4   4.000                                                                              11.35                                                                              -735.03                                                                            6.83                                                                               -735.20                                                                            2.28                                                                               -829.65                                                                            .00 .00                                        5   3.000                                                                              15.86                                                                              -737.82                                                                            11.13                                                                              -743.46                                                                            6.37                                                                               -791.75                                                                            3.99                                                                               -753.58                                    6   2.500                                                                              19.78                                                                              -738.79                                                                            14.87                                                                              -745.98                                                                            9.93                                                                               -782.31                                                                            7.46                                                                               -761.87                                    7   2.000                                                                              26.27                                                                              -754.87                                                                            21.06                                                                              -771.40                                                                            15.82                                                                              -819.49                                                                            13.19                                                                              -827.11                                    8   1.800                                                                              30.24                                                                              -780.84                                                                            24.84                                                                              -809.30                                                                            19.41                                                                              -880.03                                                                            16.69                                                                              -911.00                                    __________________________________________________________________________     (R,ANGLE) =                                                                            3.000                                                                              -2.663                                                                             2.500                                                                              -3.304                                                                             2.000                                                                              -4.354                                                                             1.800                                                                              -4.994                                     POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000    -5.063  -4.903  -4.657  -4.513                                     2   10.000  -5.087  -4.925  -4.675  -4.529                                     3   5.000   -5.112  -4.949  -4.695  -4.546                                     4   4.000   -5.126  -4.961  -4.705  -4.554                                     5   3.000                                                                              -5.151                                                                             .000    -4.984  -4.722  -4.568                                     6   2.500   -5.173                                                                             -5.004                                                                             .000    -4.735  -4.576                                     7   2.000   -5.199  -5.023                                                                             -4.739                                                                             .000    -4.578                                     8   1.800   -5.207  -5.027  -4.740                                                                             -4.578                                                                             .000                                       __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               -13.48                                                                             -793.16                                                                            -16.20                                                                             -806.30                                                                            -20.28                                                                             -1166.1                                                                            -22.54                                                                             -1589.2                                    2   10.000                                                                             -9.90                                                                              -795.50                                                                            -12.74                                                                             -807.71                                                                            -17.01                                                                             -1256.7                                                                            -19.37                                                                             -1808.3                                    3   5.000                                                                              -5.95                                                                              -792.89                                                                            -8.93                                                                              -806.42                                                                            -13.40                                                                             -1426.2                                                                            -15.89                                                                             -2242.4                                    4   4.000                                                                              -3.82                                                                              -796.15                                                                            -6.87                                                                              -808.00                                                                            -11.46                                                                             -1590.5                                                                            -14.01                                                                             -2682.3                                    5   3.000                                                                              .00 .00 -3.20                                                                              -817.24                                                                            -7.99                                                                              -2280.0                                                                            -10.65                                                                             -4741.0                                    6   2.500                                                                              3.32                                                                               -778.61                                                                            .00 .00 -4.97                                                                              -5443.3                                                                            -7.73                                                                              -18144.                                    7   2.000                                                                              8.80                                                                               -933.61                                                                            5.28                                                                               -1389.1                                                                            .00 .00 -2.93                                                                              661687.                                    8   1.800                                                                              12.14                                                                              -1104.2                                                                            8.50                                                                               -1863.7                                                                            3.03                                                                               -13332.                                                                            .00 .00                                        __________________________________________________________________________      Condition Corresponding Values: K.sub.aO /γ.sub.aO = 1.04, K.sub.aR      /γ.sub.aR = 0.99                                                   

                                      TABLE 26                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of                                                              Rotation and Correction Coefficient μ: (l) at Telephoto End                 (292.0 mm) of Second Embodiment                                                f = 292.0 mm                                                                   (R,ANGLE) =                                                                            .000                                                                               .000                                                                               10.000                                                                             -.715                                                                              5.000                                                                              -1.495                                                                             4.000                                                                              -1.913                                     POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000                                                                               -12.419                                                                            .000    -11.589 -10.764 -10.361                                    2   10.000  -12.924                                                                            -12.017                                                                            .000    -11.114 -10.683                                    3   5.000   -13.482 -12.476                                                                            -11.502                                                                            .000    -11.050                                    4   4.000   -13.797 -12.742 -11.738                                                                            -11.262                                                                            .000                                       5   3.000   -14.388 -13.238 -12.153 -11.632                                    6   2.500   -14.933 -13.693 -12.531 -11.976                                    7   2.000   -15.912 -14.503 -13.197 -12.580                                    8   1.800   -16.560 -15.033 -13.628 -12.967                                    __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               .00 .00 -8.28                                                                              -232.56                                                                            -16.09                                                                             -250.81                                                                            -19.82                                                                             -247.76                                    2   10.000                                                                             9.24                                                                               -227.47                                                                            .00 .00 -8.67                                                                              -257.33                                                                            -12.80                                                                             -248.97                                    3   5.000                                                                              20.16                                                                              -235.49                                                                            9.74                                                                               -255.32                                                                            .00 .00 -4.62                                                                              -245.25                                    4   4.000                                                                              26.40                                                                              -237.92                                                                            15.27                                                                              -253.37                                                                            4.91                                                                               -239.45                                                                            .00 .00                                        5   3.000                                                                              38.24                                                                              -241.22                                                                            25.72                                                                              -253.19                                                                            14.13                                                                              -249.72                                                                            8.66                                                                               -263.45                                    6   2.500                                                                              49.29                                                                              -243.49                                                                            35.41                                                                              -253.90                                                                            22.63                                                                              -252.97                                                                            16.62                                                                              -262.17                                    7   2.000                                                                              69.33                                                                              -246.53                                                                            52.83                                                                              -255.42                                                                            37.77                                                                              -256.28                                                                            30.74                                                                              -262.84                                    8   1.800                                                                              82.80                                                                              -248.34                                                                            64.42                                                                              -256.73                                                                            47.76                                                                              -258.38                                                                            40.03                                                                              -264.36                                    __________________________________________________________________________     (R,ANGLE) =                                                                            3.000                                                                              -2.658                                                                             2.500                                                                              -3.301                                                                             2.000                                                                              -4.357                                                                             1.800                                                                              -5.000                                     POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000    -9.704  -9.191  -8.443  -8.035                                     2   10.000  -9.982  -9.438  -8.647  -8.218                                     3   5.000   -10.298 -9.717  -8.877  -8.423                                     4   4.000   -10.473 -9.871  -9.003  -8.535                                     5   3.000                                                                              -10.801                                                                            .000    -10.155 -9.235  -8.740                                     6   2.500   -11.089                                                                            -10.416                                                                            .000    -9.442  -8.922                                     7   2.000   -11.598 -10.854                                                                            -9.794                                                                             .000    -9.226                                     8   1.800   -11.922 -11.132 -10.009                                                                            -9.402                                                                             .000                                       __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               -25.79                                                                             -253.99                                                                            -30.34                                                                             -257.91                                                                            -36.79                                                                             -266.67                                                                            -40.18                                                                             -276.37                                    2   10.000                                                                             -19.40                                                                             -255.99                                                                            -24.41                                                                             -259.81                                                                            -31.50                                                                             -269.00                                                                            -35.22                                                                             -279.62                                    3   5.000                                                                              -11.97                                                                             -257.37                                                                            -17.55                                                                             -261.27                                                                            -25.41                                                                             -271.36                                                                            -29.52                                                                             -283.38                                    4   4.000                                                                              -7.80                                                                              -257.24                                                                            -13.70                                                                             -261.62                                                                            -22.00                                                                             -272.61                                                                            -26.34                                                                             -285.64                                    5   3.000                                                                              .00 .00 -6.53                                                                              -259.93                                                                            -15.70                                                                             -275.04                                                                            -20.47                                                                             -290.55                                    6   2.500                                                                              7.13                                                                               -267.48                                                                            .00 .00 -9.98                                                                              -278.09                                                                            -15.16                                                                             -296.75                                    7   2.000                                                                              19.71                                                                              -266.91                                                                            11.47                                                                              -272.88                                                                            .00 .00 -5.93                                                                              -317.27                                    8   1.800                                                                              27.92                                                                              -269.03                                                                            18.91                                                                              -275.52                                                                            6.43                                                                               -292.78                                                                            .00 .00                                        __________________________________________________________________________      Condition Corresponding Values: K.sub.aO /γ.sub.aO = 1.33, K.sub.aR      /γ.sub.aR = 0.85                                                   

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end, middle position, and telephoto end in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the second embodiment of the present invention are as follows.

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement                                                                       Closest Arrangement                                                K.sub.aO /γ.sub.aO                                                                   K.sub.aK /γ.sub.aK                                  ______________________________________                                         Wide-angle End                                                                            2.75          0.44                                                  (F = 36.0)                                                                     Middle Position                                                                           3.36          0.43                                                  (F = 50.0)                                                                     Telephoto End                                                                             3.80          0.43                                                  (F = 103.0)                                                                    Second Embodiment                                                              Wide-angle End                                                                            0.88          1.15                                                  (F = 103.0)                                                                    Middle Position                                                                           1.04          0.99                                                  (F = 200.0)                                                                    Telephoto End                                                                             1.33          0.85                                                  (F = 292.0)                                                                    ______________________________________                                    

As described above, in the second embodiment as well, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced. For this reason, an error of the conversion coefficient K_(a) calculated based on γ_(a) and μ or an error from the actual lens driving amount Δa obtained when only one pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set can be reduced.

Next, in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the second embodiment of the present invention, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                            -4.4%          -13.0%                                               (F = 36.0)                                                                     Middle Position                                                                           -11.8%         -12.0%                                               (F = 50.0)                                                                     Telephoto End                                                                             -12.6%         -14.6%                                               (F = 103.0)                                                                    Second Embodiment                                                              Wide-angle End                                                                            -0.7%          -0.4%                                                (F = 103.0)                                                                    Middle Position                                                                           -0.3%          -0.7%                                                (F = 200.0)                                                                    Telephoto End                                                                             -0.7%          -0.5%                                                (F = 292.0)                                                                    ______________________________________                                    

As described above, in the second embodiment as well, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Table 27 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 19) of the second embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

Note that the arrangement of the table and reference symbols are the same as those in the first embodiment. The upper table in Table 27 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=10.0, 5.0, 3.5, 2.5, 2.0, and 1.8 m) in the respective zooming states of the focal lengths (F=103.0, 150.0, 200.0, 250.0, and 292.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and photographing distances.

                                      TABLE 27                                     __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Second Embodiment                                     1.80 m                                                                              2.00 m                                                                              2.50 m                                                                              3.00 m                                                                              5.00 m                                                                              10.00 m                                       __________________________________________________________________________     F 103.000 Bf                                                                           .000 .000 .000 .000 .000 .000                                          F 150.000 Bf                                                                           -.015                                                                               -.015                                                                               -.014                                                                               -.007                                                                               .001 .005                                          F 200.000 Bf                                                                           -.029                                                                               -.014                                                                               .014 .026 .021 .008                                          F 250.000 Bf                                                                           .048 .034 -.006                                                                               -.038                                                                               -.046                                                                               -.030                                         F 292.000 Bf                                                                           .000 .000 .000 .000 .000 .000                                            ANGLE DA                                                                             -5.000                                                                              -4.357                                                                              -3.301                                                                              -2.225                                                                              -1.495                                                                              -.715                                         F 103.000 DX                                                                           .000 -10.734                                                                             .000 .000 .000 R                                                                              1.80 m                                        F 150.000 DX                                                                           .000 -11.285                                                                             .000 .000 .000 R                                                                              1.80 m                                        F 200.000 DX                                                                           .000 -12.161                                                                             .000 .000 .000 R                                                                              1.80 m                                        F 250.000 DX                                                                           .000 -13.403                                                                             .000 .000 .000 R                                                                              1.80 m                                        F 292.000 DX                                                                           .000 -14.889                                                                             .000 .000 .000 R                                                                              1.80 m                                        F 103.000 DX                                                                           .000 -9.484                                                                              .000 .000 .000 R                                                                              2.00 m                                        F 150.000 DX                                                                           .000 -9.962                                                                              .000 .000 .000 R                                                                              2.00 m                                        F 200.000 DX                                                                           .000 -10.715                                                                             .000 .000 .000 R                                                                              2.00 m                                        F 250.000 DX                                                                           .000 -11.799                                                                             .000 .000 .000 R                                                                              2.00 m                                        F 292.000 DX                                                                           .000 -13.077                                                                             .000 .000 .000 R                                                                              2.00 m                                        F 103.000 DX                                                                           .000 -7.346                                                                              .000 .000 .000 R                                                                              2.50 m                                        F 150.000 DX                                                                           .000 -7.705                                                                              .000 .000 .000 R                                                                              2.50 m                                        F 200.000 DX                                                                           .000 -8.255                                                                              .000 .000 .000 R                                                                              2.50 m                                        F 250.000 DX                                                                           .000 -9.090                                                                              .000 .000 .000 R                                                                              2.50 m                                        F 292.000 DX                                                                           .000 -10.028                                                                             .000 .000 .000 R                                                                              2.50 m                                        F 103.000 DX                                                                           .000 -5.063                                                                              .000 .000 .000 R                                                                              3.50 m                                        F 150.000 DX                                                                           .000 -5.298                                                                              .000 .000 .000 R                                                                              3.50 m                                        F 200.000 DX                                                                           .000 -5.659                                                                              .000 .000 .000 R                                                                              3.50 m                                        F 250.000 DX                                                                           .000 -6.232                                                                              .000 .000 .000 R                                                                              3.50 m                                        F 292.000 DX                                                                           .000 -6.840                                                                              .000 .000 .000 R                                                                              3.50 m                                        F 103.000 DX                                                                           .000 -3.453                                                                              .000 .000 .000 R                                                                              5.00 m                                        F 150.000 DX                                                                           .000 -3.604                                                                              .000 .000 .000 R                                                                              5.00 m                                        F 200.000 DX                                                                           .000 -3.847                                                                              .000 .000 .000 R                                                                              5.00 m                                        F 250.000 DX                                                                           .000 -4.237                                                                              .000 .000 .000 R                                                                              5.00 m                                        F 292.000 DX                                                                           .000 -4.632                                                                              .000 .000 .000 R                                                                              5.00 m                                        F 103.000 DX                                                                           .000 -1.677                                                                              .000 .000 .000 R                                                                              10.00 m                                       F 150.000 DX                                                                           .000 -1.744                                                                              .000 .000 .000 R                                                                              10.00 m                                       F 200.000 DX                                                                           .000 -1.863                                                                              .000 .000 .000 R                                                                              10.00 m                                       F 250.000 DX                                                                           .000 -2.048                                                                              .000 .000 .000 R                                                                              10.00 m                                       F 292.000 DX                                                                           .000 -2.231                                                                              .000 .000 .000 R                                                                              10.00 m                                       __________________________________________________________________________

As can be seen from Table 27, so-called manual focusing can be attained in the zoom lens according to the second embodiment since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

Third Embodiment!

The third embodiment is directed to a zoom lens which has a five-unit arrangement, i.e., negative, positive, positive, negative and positive lens units, and attains focusing by a positive second lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=0.6 m) to the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=77.5) is set to be 0.70.

Table 28 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the third embodiment.

The upper table in Table 28 summarizes the focal lengths and principal point interval data of the respective lens units of the optical system corresponding to the third embodiment in association with six zooming states (focal length F=28.8 (1-POS), 35.0 (2-POS), 50.0 (3-POS), 60.0 (4-POS), 68.0 (5-POS), and 77.5 mm (6-POS)).

The middle table in Table 28 summarizes spline sample data when the shape of the focus cam in the second lens unit of the third embodiment, which is used for focusing, is expressed by the above-mentioned spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), (4), and (5) correspond to the first, second, third, fourth, and fifth lens units, respectively.

Furthermore, the lower table in Table 28 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (focal length F=28.8, 35.0, 50.0, 60.0, 68.0, and 77.5 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.0, 2.0, 1.0, 0.8, and 0.6 m) using the focus cam of the third embodiment. In this table, since the amount of rotation for zooming from the wide-angle end (F=28.8) to the telephoto end (F=77.5) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=0.6 m) is set to be 7.0, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the second embodiment is 0.70.

                                      TABLE 28                                     __________________________________________________________________________     Third Embodiment f = 28.8 to 77.5                                              (Rotation Amount Ratio: a.sub.F /a.sub.Z = 0.70)                               Focal lengths and Principal Point Intervals of                                 Lens Units of Third Embodiment                                                           1-POS                                                                               2-POS                                                                               3-POS                                                                               4-POS                                                                               5-POS                                                                               6-POS                                       __________________________________________________________________________             F 28.8000                                                                             35.0000                                                                             50.0000                                                                             60.0000                                                                             68.0000                                                                             77.5000                                     F1 -46.0000                                                                            D1                                                                               62.6883                                                                             48.0215                                                                             27.9560                                                                             20.3988                                                                             16.0652                                                                             12.1755                                     F2 125.0000                                                                            D2                                                                               12.8909                                                                             12.8909                                                                             12.8909                                                                             12.8909                                                                             12.8909                                                                             12.8909                                     F3 56.6000                                                                             D3                                                                               11.1791                                                                             14.7864                                                                             23.6307                                                                             29.5541                                                                             34.2839                                                                             39.8576                                     F4 -62.0000                                                                            D4                                                                               27.4694                                                                             25.5819                                                                             21.1703                                                                             18.5006                                                                             16.6129                                                                             14.5291                                     F5 65.0000                                                                             D5                                                                               50.0476                                                                             52.5224                                                                             58.5440                                                                             62.5164                                                                             65.6364                                                                             69.2832                                     __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point)                            Corresponding to Third Embodiment                                                 ANGLE (1)   (2)   (3)   (4)   (5)                                           __________________________________________________________________________      1 -1.0000                                                                              .0000 .5760 .0000 .0000 .0000                                          2 0.0000                                                                               .0000 .0000 .0000 .0000 .0000                                          3 0.7488                                                                               .0000 -.4431                                                                               .0000 .0000 .0000                                          4 1.2605                                                                               .0000 -.7533                                                                               .0000 .0000 .0000                                          5 1.9139                                                                               .0000 -1.1588                                                                              .0000 .0000 .0000                                          6 3.9766                                                                               .0000 -2.5100                                                                              .0000 .0000 .0000                                          7 5.0694                                                                               .0000 -3.2733                                                                              .0000 .0000 .0000                                          8 7.0000                                                                               .0000 -4.7038                                                                              .0000 .0000 .0000                                          9 10.0000                                                                              .0000 -7.0005                                                                              .0000 .0000 .0000                                         10 10.7488                                                                              .0000 -7.6079                                                                              .0000 .0000 .0000                                         11 11.2605                                                                              .0000 -8.0299                                                                              .0000 .0000 .0000                                         12 11.9139                                                                              .0000 -8.5780                                                                              .0000 .0000 .0000                                         13 13.9766                                                                              .0000 -10.3745                                                                             .0000 .0000 .0000                                         14 15.0694                                                                              .0000 -11.3698                                                                             .0000 .0000 .0000                                         15 17.0000                                                                              .0000 -13.1983                                                                             .0000 .0000 .0000                                         16 20.0000                                                                              .0000 -16.1500                                                                             .0000 .0000 .0000                                         __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation                          for Focusing of Third Embodiment                                               (Rotation Amount Ratio: a.sub.F /a.sub.Z = 0.70)                                        Infinity            Amount of                                                  Correspond-                                                                              Photograph-                                                                              Rotation for                                      Focal Length                                                                            ing Position                                                                             ing Distance                                                                             Focusing                                          __________________________________________________________________________     28.8 mm  .0000     5.00 m    .749                                              35.0 mm  1.1000    3.00 m    1.260                                             50.0 mm  4.1000    2.00 m    1.914                                             60.0 mm  6.6000    1.00 m    3.977                                             68.0 mm  8.3000    0.80 m    5.069                                             77.5 mm  10.0000   0.60 m    7.000                                             __________________________________________________________________________     Condition Corresponding Value (1)                                                               1.01 (wide-angle end)                                                                     1.08 (telephoto end)                               Condition Corresponding Value (2)                                                               1.32                                                          Condition Corresponding Value (3)                                                               0.70                                                          Condition Corresponding Value (4)                                                               1.30 (wide-angle end)                                                                     1.30 (telephoto end)                               Condition Corresponding Value (5)                                                               1.21 (wide-angle end)                                                                     1.30 (telephoto end)                               Condition Corresponding Value (6)                                                               0.85 (wide-angle end)                                                                     0.79 (telephoto end)                               __________________________________________________________________________

Table 29 below summarizes the numerical value data of the cams of the focusing lens unit in the third embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 28. Note that the meanings of the reference symbols in Table 29 are the same as those in the first embodiment.

                  TABLE 29                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit                                 in Third Embodiment                                                            Focus Cam Numerical Value Data                                                 ANGLE          (2)          F                                                  ______________________________________                                         .0000          .0000        28.8000                                            .5000          -.2945       31.6324                                            1.0000         -.5946       34.4414                                            1.5000         -.9007       37.2175                                            2.0000         -1.2131      39.9286                                            2.5000         -1.5317      42.5387                                            3.0000         -1.8566      45.0236                                            3.5000         -2.1880      47.3702                                            4.0000         -2.5259      49.5758                                            4.5000         -2.8707      51.6494                                            5.0000         -3.2236      53.6383                                            5.5000         -3.5855      55.5935                                            6.0000         -3.9546      57.5588                                            6.5000         -4.3283      59.5828                                            7.0000         -4.7038      61.7251                                            7.5000         -5.0792      64.0159                                            8.0000         -5.4553      66.4609                                            8.5000         -5.8338      69.0539                                            9.0000         -6.2164      71.7776                                            9.5000         -6.6048      74.6064                                            10.0000        -7.0005      77.5000                                            10.5000        -7.4045      0.0000                                             11.0000        -7.8144      0.0000                                             11.5000        -8.2296      0.0000                                             12.0000        -8.6510      0.0000                                             12.5000        -9.0781      0.0000                                             13.0000        -9.5111      0.0000                                             13.5000        -9.9501      0.0000                                             14.0000        -10.3955     0.0000                                             14.5000        -10.8473     0.0000                                             15.0000        -11.3057     0.0000                                             15.5000        -11.7704     0.0000                                             16.0000        -12.2411     0.0000                                             16.5000        -12.7173     0.0000                                             17.0000        -13.1983     0.0000                                             ______________________________________                                         Zoom Compensation Cam Numerical Value Data                                     ANGLE          (2)          F                                                  ______________________________________                                         .0000          .0000        28.8000                                            .5000          2.2025       31.6324                                            1.0000         4.4083       34.4414                                            1.5000         6.6130       37.2175                                            2.0000         8.7944       39.9286                                            2.5000         10.9260      42.5387                                            3.0000         12.9891      45.0236                                            3.5000         14.9728      47.3702                                            4.0000         16.8733      49.5758                                            4.5000         18.6957      51.6494                                            5.0000         20.4741      53.6383                                            5.5000         22.2461      55.5935                                            6.0000         24.0423      57.5588                                            6.5000         25.8966      59.5828                                            7.0000         27.8527      61.7251                                            7.5000         29.9315      64.0159                                            8.0000         32.1370      66.4609                                            8.5000         34.4630      69.0539                                            9.0000         36.8943      71.7776                                            9.5000         39.4092      74.6064                                            10.0000        41.9743      77.5000                                            ______________________________________                                    

The left table in Table 29 summarizes the numerical value data of the focus cam of the third embodiment, and the right table in Table 29 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amounts (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) coincides with the movement locus of the second lens unit calculated using the paraxial data in the upper table in Table 28.

Tables 30, 31, and 32 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(x) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=28.8), the middle position (F=50.0), and the telephoto end (F=77.5) according to the third embodiment, respectively. The arrangements of the respective tables and the meanings of the reference symbols are the same as those in the first embodiment.

                                      TABLE 30                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical                Axis at Wide-angle End (28.8 mm) in Third Embodiment                           __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .000                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               .372                                                                               1) .000                                                                             2) -.218                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               .749                                                                               1) .000                                                                             2) -.443                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               1.260                                                                              1) .000                                                                             2) -.753                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               1.914                                                                              1) .000                                                                             2) -1.159                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.000                                                                              ANG                                                                               3.977                                                                              1) .000                                                                             2) -2.510                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R .800                                                                               ANG                                                                               5.069                                                                              1) .000                                                                             2) -3.273                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R .600                                                                               ANG                                                                               7.000                                                                              1) .000                                                                             2) -4.704                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Wide-angle                 End (28.8 mm) in Third Embodiment                                              __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 7.663                                                                             3) -.072                                                                            4) 4.952                                                                            5) .230                                      R 10.000                                                                             ANG                                                                               .372                                                                               1) .005                                                                             2) 7.665                                                                             3) -.072                                                                            4) 7.952                                                                            5) .230                                      R 5.000                                                                              ANG                                                                               .749                                                                               1) .009                                                                             2) 7.667                                                                             3) -.072                                                                            4) 4.952                                                                            5) .230                                      R 3.000                                                                              ANG                                                                               1.260                                                                              1) .016                                                                             2) 7.669                                                                             3) -.072                                                                            4) 4.952                                                                            5) .230                                      R 2.000                                                                              ANG                                                                               1.914                                                                              1) .025                                                                             2) 7.672                                                                             3) -.072                                                                            4) 4.952                                                                            5) .230                                      R 1.000                                                                              ANG                                                                               3.977                                                                              1) .054                                                                             2) 7.683                                                                             3) -.072                                                                            4) 4.952                                                                            5) .230                                      R .800                                                                               ANG                                                                               5.069                                                                              1) .070                                                                             2) 7.689                                                                             3) -.072                                                                            4) 4.952                                                                            5) .230                                      R .600                                                                               ANG                                                                               7.000                                                                              1) .101                                                                             2) 7.701                                                                             3) -.072                                                                            4) 4.952                                                                            5) .230                                      __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction                 of Optical Axis at Wide-angle End (28.8 mm) in Third Embodiment                __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -.385                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               .372                                                                               1) .000                                                                             2) -.385                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               .749                                                                               1) .000                                                                             2) -.386                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               1.260                                                                              1) .000                                                                             2) -.386                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               1.914                                                                              1) .000                                                                             2) -.386                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.000                                                                              ANG                                                                               3.977                                                                              1) .000                                                                             2) -.387                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R .800                                                                               ANG                                                                               5.069                                                                              1) .000                                                                             2) -.388                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R .600                                                                               ANG                                                                               7.000                                                                              1) .000                                                                             2) -.389                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Wide-angle End (28.8 mm)                           in Third Embodiment                                                            __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -.583                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               .372                                                                               1) .000                                                                             2) -.592                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               .749                                                                               1) .000                                                                             2) -.600                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               1.260                                                                              1) .000                                                                             2) -.612                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               1.914                                                                              1) .000                                                                             2) -.629                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.000                                                                              ANG                                                                               3.977                                                                              1) .000                                                                             2) -.682                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R .800                                                                               ANG                                                                               5.069                                                                              1) .000                                                                             2) -.717                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R .600                                                                               ANG                                                                               7.000                                                                              1) .000                                                                             2) -.751                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction                 of Rotation at Wide-angle End (28.8 mm) in Third Embodiment                    __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .225                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               .372                                                                               1) .000                                                                             2) .228                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               .749                                                                               1) .000                                                                             2) .231                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               1.260                                                                              1) .000                                                                             2) .236                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               1.914                                                                              1) .000                                                                             2) .243                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 1.000                                                                              ANG                                                                               3.977                                                                              1) .000                                                                             2) .264                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R .800                                                                               ANG                                                                               5.069                                                                              1) .000                                                                             2) .278                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R .600                                                                               ANG                                                                               7.000                                                                              1) .000                                                                             2) .292                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 1.01,         γ.sub.aR /γ.sub.aO = 1.30                                    

                                      TABLE 31                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction                           of Optical Axis at Middle Position (50.0 mm)                                   in Third Embodiment                                                            R .000                                                                               ANG                                                                               .000                                                                              1)                                                                               .000                                                                              2)                                                                               .000                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 10.000                                                                             ANG                                                                               .372                                                                              1)                                                                               .000                                                                              2)                                                                               -.257                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 5.000                                                                              ANG                                                                               .747                                                                              1)                                                                               .000                                                                              2)                                                                               -.520                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 3.000                                                                              ANG                                                                               1.250                                                                             1)                                                                               .000                                                                              2)                                                                               -.882                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 2.000                                                                              ANG                                                                               1.888                                                                             1)                                                                               .000                                                                              2)                                                                               -1.351                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 1.000                                                                              ANG                                                                               3.936                                                                             1)                                                                               .000                                                                              2)                                                                               -2.888                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .800                                                                               ANG                                                                               5.050                                                                             1)                                                                               .000                                                                              2)                                                                               -3.738                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .600                                                                               ANG                                                                               6.995                                                                             1)                                                                               .000                                                                              2)                                                                               -5.298                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       Imaging Magnification β.sub.K  of Lens Units at Middle Position           (50.0 mm) in Third Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                              1)                                                                               .000                                                                              2)                                                                               2.449                                                                              3)                                                                               -.412                                                                             4)                                                                               10.848                                                                             5)                                                                               .099                                       R 10.000                                                                             ANG                                                                               .372                                                                              1)                                                                               .005                                                                              2)                                                                               2.451                                                                              3)                                                                               -.412                                                                             4)                                                                               10.848                                                                             5)                                                                               .099                                       R 5.000                                                                              ANG                                                                               .747                                                                              1)                                                                               .009                                                                              2)                                                                               2.453                                                                              3)                                                                               -.412                                                                             4)                                                                               10.848                                                                             5)                                                                               .099                                       R 3.000                                                                              ANG                                                                               1.250                                                                             1)                                                                               .016                                                                              2)                                                                               2.456                                                                              3)                                                                               -.412                                                                             4)                                                                               10.848                                                                             5)                                                                               .099                                       R 2.000                                                                              ANG                                                                               1.888                                                                             1)                                                                               .024                                                                              2)                                                                               2.460                                                                              3)                                                                               -.412                                                                             4)                                                                               10.848                                                                             5)                                                                               .099                                       R 1.000                                                                              ANG                                                                               3.936                                                                             1)                                                                               .052                                                                              2)                                                                               2.472                                                                              3)                                                                               -.412                                                                             4)                                                                               10.848                                                                             5)                                                                               .099                                       R .800                                                                               ANG                                                                               5.050                                                                             1)                                                                               .068                                                                              2)                                                                               2.479                                                                              3)                                                                               -.412                                                                             4)                                                                               10.848                                                                             5)                                                                               .099                                       R .600                                                                               ANG                                                                               6.995                                                                             1)                                                                               .096                                                                              2)                                                                               2.491                                                                              3)                                                                               -.412                                                                             4)                                                                               10.848                                                                             5)                                                                               .099                                       Conversion Coefficient, γ.sub.x  Associated With Direction of            Optical Axis at Middle Position (50.0 mm) in Third Embodiment                  R .000                                                                               ANG                                                                               .000                                                                              1)                                                                               .000                                                                              2)                                                                               -.984                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 10.000                                                                             ANG                                                                               .372                                                                              1)                                                                               .000                                                                              2)                                                                               -.986                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 5.000                                                                              ANG                                                                               .747                                                                              1)                                                                               .000                                                                              2)                                                                               -.988                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 3.000                                                                              ANG                                                                               1.250                                                                             1)                                                                               .000                                                                              2)                                                                               -.991                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 2.000                                                                              ANG                                                                               1.888                                                                             1)                                                                               .000                                                                              2)                                                                               -.995                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 1.000                                                                              ANG                                                                               3.936                                                                             1)                                                                               .000                                                                              2)                                                                               -1.007                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .800                                                                               ANG                                                                               5.050                                                                             1)                                                                               .000                                                                              2)                                                                               -1.013                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .600                                                                               ANG                                                                               6.995                                                                             1)                                                                               .000                                                                              2)                                                                               -1.026                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       Slope (dx/da of Focus Cam at Middle Position                                   (50.0 mm) in Third Embodiment                                                  R .000                                                                               ANG                                                                               .000                                                                              1)                                                                               .000                                                                              2)                                                                               -.685                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 10.000                                                                             ANG                                                                               .372                                                                              1)                                                                               .000                                                                              2)                                                                               -.696                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 5.000                                                                              ANG                                                                               .747                                                                              1)                                                                               .000                                                                              2)                                                                               -.709                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 3.000                                                                              ANG                                                                               1.250                                                                             1)                                                                               .000                                                                              2)                                                                               -.727                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 2.000                                                                              ANG                                                                               1.888                                                                             1)                                                                               .000                                                                              2)                                                                               -.744                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 1.000                                                                              ANG                                                                               3.936                                                                             1)                                                                               .000                                                                              2)                                                                               -.754                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .800                                                                               ANG                                                                               5.050                                                                             1)                                                                               .000                                                                              2)                                                                               -.774                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .600                                                                               ANG                                                                               6.995                                                                             1)                                                                               .000                                                                              2)                                                                               -.827                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       Conversion Coefficient γ.sub.a  Associated With Direction of             Rotation at Middle Position (50.0 mm) in Third Embodiment                      R .000                                                                               ANG                                                                               .000                                                                              1)                                                                               .000                                                                              2)                                                                               .675                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 10.000                                                                             ANG                                                                               .372                                                                              1)                                                                               .000                                                                              2)                                                                               .687                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 5.000                                                                              ANG                                                                               .747                                                                              1)                                                                               .000                                                                              2)                                                                               .701                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 3.000                                                                              ANG                                                                               1.250                                                                             1)                                                                               .000                                                                              2)                                                                               .721                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 2.000                                                                              ANG                                                                               1.888                                                                             1)                                                                               .000                                                                              2)                                                                               .740                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 1.000                                                                              ANG                                                                               3.936                                                                             1)                                                                               .000                                                                              2)                                                                               .760                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .800                                                                               ANG                                                                               5.050                                                                             1)                                                                               .000                                                                              2)                                                                               .784                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .600                                                                               ANG                                                                               6.995                                                                             1)                                                                               .000                                                                              2)                                                                               .848                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 1.04,         γ.sub.aR /γ.sub.aO  = 1.26                                   

                                      TABLE 32                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of                        Optical Axis at Telephoto End (77.5 mm)                                        in Third Embodiment                                                            R .000                                                                               ANG                                                                               .000                                                                              1)                                                                               .000                                                                              2)                                                                               .000                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 10.000                                                                             ANG                                                                               .372                                                                              1)                                                                               .000                                                                              2)                                                                               -.300                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 5.000                                                                              ANG                                                                               .749                                                                              1)                                                                               .000                                                                              2)                                                                               -.607                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 3.000                                                                              ANG                                                                               1.260                                                                             1)                                                                               .000                                                                              2)                                                                               -1.029                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 2.000                                                                              ANG                                                                               1.914                                                                             1)                                                                               .000                                                                              2)                                                                               -1.577                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 1.000                                                                              ANG                                                                               3.977                                                                             1)                                                                               .000                                                                              2)                                                                               -3.374                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .800                                                                               ANG                                                                               5.069                                                                             1)                                                                               .000                                                                              2)                                                                               -4.369                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .600                                                                               ANG                                                                               7.000                                                                             1)                                                                               .000                                                                              2)                                                                               -6.198                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       Imaging Magnification β.sub.K  of Lens Units at Telephoto                 End (77.5 mm) in Third Embodiment                                              R .000                                                                               ANG                                                                               .000                                                                              1)                                                                               .000                                                                              2)                                                                               1.871                                                                              3)                                                                               -.869                                                                             4)                                                                               -15.724                                                                            5)                                                                               -.066                                      R 10.000                                                                             ANG                                                                               .372                                                                              1)                                                                               .005                                                                              2)                                                                               1.873                                                                              3)                                                                               -.869                                                                             4)                                                                               -15.724                                                                            5)                                                                               -.066                                      R 5.000                                                                              ANG                                                                               .749                                                                              1)                                                                               .009                                                                              2)                                                                               1.875                                                                              3)                                                                               -.869                                                                             4)                                                                               -15.724                                                                            5)                                                                               -.066                                      R 3.000                                                                              ANG                                                                               1.260                                                                             1)                                                                               .016                                                                              2)                                                                               1.879                                                                              3)                                                                               .869                                                                              4)                                                                               -15.724                                                                            5)                                                                               -.066                                      R 2.000                                                                              ANG                                                                               1.914                                                                             1)                                                                               .025                                                                              2)                                                                               1.883                                                                              3)                                                                               -.869                                                                             4)                                                                               -15.724                                                                            5)                                                                               -.066                                      R 1.000                                                                              ANG                                                                               3.977                                                                             1)                                                                               .053                                                                              2)                                                                               1.898                                                                              3)                                                                               -.869                                                                             4)                                                                               -15.724                                                                            5)                                                                               -.066                                      R .800                                                                               ANG                                                                               5.069                                                                             1)                                                                               .068                                                                              2)                                                                               1.906                                                                              3)                                                                               -.869                                                                             4)                                                                               -15.724                                                                            5)                                                                               -.066                                      R .600                                                                               ANG                                                                               7.000                                                                             1)                                                                               .097                                                                              2)                                                                               1.920                                                                              3)                                                                               -.869                                                                             4)                                                                               -15.724                                                                            5)                                                                               -.066                                      Conversion Coefficient γ.sub.x  Associated With Direction of             Optical Axis at Telephoto End (77.5 mm) in Third Embodiment                    R .000                                                                               ANG                                                                               .000                                                                              1)                                                                               .000                                                                              2)                                                                               -2.027                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 10.000                                                                             ANG                                                                               .372                                                                              1)                                                                               .000                                                                              2)                                                                               -2.035                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 5.000                                                                              ANG                                                                               .749                                                                              1)                                                                               .000                                                                              2)                                                                               -2.042                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 3.000                                                                              ANG                                                                               1.260                                                                             1)                                                                               .000                                                                              2)                                                                               -2.052                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 2.000                                                                              ANG                                                                               1.914                                                                             1)                                                                               .000                                                                              2)                                                                               -2.066                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 1.000                                                                              ANG                                                                               3.977                                                                             1)                                                                               .000                                                                              2)                                                                               -2.110                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .800                                                                               ANG                                                                               5.069                                                                             1)                                                                               .000                                                                              2)                                                                               -2.134                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .600                                                                               ANG                                                                               7.000                                                                             1)                                                                               .000                                                                              2)                                                                               -2.180                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       Slope dx/da of Focus Cam at Telephoto End (77.5 mm)                            in Third Embodiment                                                            R .000                                                                               ANG                                                                               .000                                                                              1)                                                                               .000                                                                              2)                                                                               -.800                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 10.000                                                                             ANG                                                                               .372                                                                              1)                                                                               .000                                                                              2)                                                                               -.812                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 5.000                                                                              ANG                                                                               .749                                                                              1)                                                                               .000                                                                              2)                                                                               -.820                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 3.000                                                                              ANG                                                                               1.260                                                                             1)                                                                               .000                                                                              2)                                                                               -.831                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 2.000                                                                              ANG                                                                               1.914                                                                             1)                                                                               .000                                                                              2)                                                                               -.847                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 1.000                                                                              ANG                                                                               3.977                                                                             1)                                                                               .000                                                                              2)                                                                               -.897                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .800                                                                               ANG                                                                               5.069                                                                             1)                                                                               .000                                                                              2)                                                                               -.925                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .600                                                                               ANG                                                                               7.000                                                                             1)                                                                               .000                                                                              2)                                                                               -.967                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       Conversion Coefficient γ.sub.a  Associated With Direction of             Rotation at Telephoto End (77.5 mm) in Third Embodiment                        R .000                                                                               ANG                                                                               .000                                                                              1)                                                                               .000                                                                              2)                                                                               1.622                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 10.000                                                                             ANG                                                                               .372                                                                              1)                                                                               .000                                                                              2)                                                                               1.651                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 5.000                                                                              ANG                                                                               .749                                                                              1)                                                                               .000                                                                              2)                                                                               1.674                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 3.000                                                                              ANG                                                                               1.260                                                                             1)                                                                               .000                                                                              2)                                                                               1.705                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 2.000                                                                              ANG                                                                               1.914                                                                             1)                                                                               .000                                                                              2)                                                                               1.749                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R 1.000                                                                              ANG                                                                               3.977                                                                             1)                                                                               .000                                                                              2)                                                                               1.892                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .800                                                                               ANG                                                                               5.069                                                                             1)                                                                               .000                                                                              2)                                                                               1.974                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       R .600                                                                               ANG                                                                               7.000                                                                             1)                                                                               .000                                                                              2)                                                                               2.107                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                       __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0  = 1.08,        γ.sub.aR /γ.sub.a0  = 1.30                                   

As can be seen from Tables 30, 31, and 32, at each focal length, the value of the conversion coefficient γ_(x) associated with the direction of the optical axis, and the value of the slope (dx/da) of the focus cam increases as the photographing distance becomes closer to the closest distance. However, since the degree of the changes is small in any case, the with the changes in the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, becomes small.

From Tables 30, 31, and 32, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×1.30 at the wide-angle end (F=28.8), ×1.26 at the middle position (F=50.0), and ×1.30 at the telephoto end (F =77.5). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the third embodiment is calculated using formula (a), and is compared with that in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values:

Embodiment of Japanese Patent Application

Laid-Open No. 5-142475

    N.sub.W >9.3 N.sub.M >10.1 N.sub.T >8.1

Third Embodiment

    N.sub.W >1.4 N.sub.M >1.3 N.sub.T >1.4

Therefore, as can be seen from a comparison with the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the values of the numbers N of divisions become very small.

As described above, in the third embodiment as well, since the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation is much smaller than that in the conventional system so that the number of data of the conversion coefficient γ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Tables 33, 34, and 35 summarize the calculation results of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=28.8), middle position (F=50.0), and telephoto end (F =77.5) according to the third embodiment. The arrangements of the tables and reference symbols are the same as those in the first embodiment. The position of the focusing lens in the first pair in the upper two tables in each of Tables 33, 34, and 35, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position.

Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 33, 34, and 35, i.e., in the ninth and tenth columns is (R, ANGLE)=(0.6, 7.0), and it indicates that this position corresponds to the closest in-focus (R=0.6 m) corresponding position.

                                      TABLE 33                                     __________________________________________________________________________     Conversion Coefficients K.sub.a :(rs), γ.sub.a :(r) Associated with      Direction of Rotation and Correction                                           Coefficient μ:(l) at Wide-angle End (28.8 mm) of Third Embodiment           f = 28.8 mm                                                                    __________________________________________________________________________     (R,ANGLE) =                                                                             .000                                                                               .000                                                                               10.000                                                                             .372                                                                               5.000                                                                              .749                                                                               3.000                                                                              1.260                                     POS R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000 .225                                                                               .000    .226    .227    .229                                      2   10.000   .227                                                                               .228                                                                               .000    .229    .231                                      3   5.000    .229    .230                                                                               .231                                                                               .000    .233                                      4   3.000    .232    .233    .235                                                                               .236                                                                               .000                                      5   2.000    .236    .237    .239    .241                                      6   1.000    .250    .251    .253    .254                                      7   .800     .258    .259    .261    .263                                      8   .600     .273    .274    .276    .278                                      __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 .00 .00 -.08                                                                               -8.97                                                                              -.17                                                                               -9.11                                                                              -.29                                                                               -8.99                                     2   10.000                                                                              .08 -8.80                                                                              .00 .00 -.09                                                                               -9.07                                                                              -.21                                                                               -8.92                                     3   5.000                                                                               .17 -8.93                                                                              .09 -9.06                                                                              .00 .00 -.12                                                                               -8.81                                     4   3.000                                                                               .29 -8.94                                                                              .21 -9.03                                                                              .12 -8.97                                                                              .00 .00                                       5   2.000                                                                               .45 -8.87                                                                              .37 -8.90                                                                              .28 -8.82                                                                              .16 -8.75                                     6   1.000                                                                               .99 -8.87                                                                              .91 -8.91                                                                              .82 -8.92                                                                              .69 -9.01                                     7   .800 1.31                                                                               -8.87                                                                              1.22                                                                               -8.91                                                                              1.13                                                                               -8.93                                                                              1.00                                                                               -9.02                                     8   .600 1.91                                                                               -8.94                                                                              1.82                                                                               -8.99                                                                              1.72                                                                               -9.03                                                                              1.59                                                                               -9.13                                     __________________________________________________________________________     (R,ANGLE) =                                                                             2.000                                                                              1.914                                                                              1.000                                                                              3.977                                                                              .800                                                                               5.069                                                                              .600                                                                               7.000                                     POS R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000     .231    .238    .242    .248                                      2   10.000   .233    .240    .244    .251                                      3   5.000    .235    .242    .246    .253                                      4   3.000    .239    .246    .250    .256                                      5   2.000                                                                               .243                                                                               .000    .250    .254    .261                                      6   1.000    .257                                                                               .264                                                                               .000    .269    .276                                      7   .800     .265    .273                                                                               .278                                                                               .000    .284                                      8   .600     .280    .288    .292                                                                               .292                                                                               .000                                      __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 -.44                                                                               -9.01                                                                              -.95                                                                               -9.52                                                                              -1.23                                                                              -9.32                                                                              -1.74                                                                              -11.60                                    2   10.000                                                                              -.36                                                                               -8.98                                                                              -.87                                                                               -9.53                                                                              -1.15                                                                              -9.30                                                                              -1.66                                                                              -11.71                                    3   5.000                                                                               -.27                                                                               -8.96                                                                              -.78                                                                               -9.55                                                                              -1.06                                                                              -9.28                                                                              -1.58                                                                              -11.84                                    4   3.000                                                                               -.16                                                                               -9.04                                                                              -.67                                                                               -9.59                                                                              -.95                                                                               -9.25                                                                              -1.47                                                                              -12.05                                    5   2.000                                                                               .00 .00 -.52                                                                               -9.64                                                                              -.80                                                                               -9.18                                                                              -1.33                                                                              -12.38                                    6   1.000                                                                               .53 -9.22                                                                              .00 .00 -.29                                                                               -8.53                                                                              -.83                                                                               -14.71                                    7   .800 .84 -9.19                                                                              .30 -9.01                                                                              .00 .00 -.55                                                                               -19.19                                    8   .600 1.42                                                                               -9.29                                                                              .87 -9.61                                                                              .56 -11.34                                                                             .00 .00                                       __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0  = 1.21, K.sub.a      /γ.sub.aR  = 0.85                                                  

                                      TABLE 34                                     __________________________________________________________________________     Conversion Coefficients K.sub.a :(rs), γ.sub.a :(r) Associated with      Direction of Rotation and Correction                                           Coefficient μ:(l) at Middle Position (50.0 mm) of Third Embodiment          f = 50.0 mm                                                                    __________________________________________________________________________     (R,ANGLE) =                                                                             .000                                                                               .000                                                                               10.000                                                                             .372                                                                               5.000                                                                              .747                                                                               3.000                                                                              1.250                                     POS R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000 .675                                                                               .000    .678    .683    .689                                      2   10.000   .683                                                                               .687                                                                               .000    .691    .698                                      3   5.000    .692    .696                                                                               .701                                                                               .000    .708                                      4   3.000    .705    .709    .714                                                                               .721                                                                               .000                                      5   2.000    .721    .725    .730    .736                                      6   1.000    .759    .762    .764    .766                                      7   .800     .777    .779    .781    .782                                      8   .600     .817    .820    .821    .823                                      POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 .00 .00 -.25                                                                               -19.88                                                                             -.51                                                                               -19.90                                                                             -.86                                                                               -19.34                                    2   10.000                                                                              .25 -20.93                                                                             .00 .00 -.26                                                                               -19.70                                                                             -.61                                                                               -19.16                                    3   5.000                                                                               .52 -20.37                                                                             .26 -19.94                                                                             .00 .00 -.36                                                                               -19.24                                    4   3.000                                                                               .88 -19.77                                                                             .62 -19.23                                                                             .36 -18.29                                                                             .00 .00                                       5   2.000                                                                               1.36                                                                               -19.89                                                                             1.10                                                                               -19.74                                                                             .83 -19.84                                                                             .47 -23.58                                    6   1.000                                                                               2.99                                                                               -23.97                                                                             2.71                                                                               -25.03                                                                             2.44                                                                               -26.90                                                                             2.06                                                                               -32.96                                    7   .800 3.92                                                                               -25.90                                                                             3.64                                                                               -27.21                                                                             3.36                                                                               -29.29                                                                             2.97                                                                               -34.98                                    8   .600 5.72                                                                               -27.01                                                                             5.43                                                                               -28.16                                                                             5.13                                                                               -29.79                                                                             4.73                                                                               -33.52                                    __________________________________________________________________________     (R,ANGLE) =                                                                             2.000                                                                              1.888                                                                              1.000                                                                              3.936                                                                              .800                                                                               5.050                                                                              .600                                                                               6.995                                     POS R    r   rs  r   rs  r   rs  r    rs                                       __________________________________________________________________________     1   .000     .696    .704    .705     .711                                     2   10.000   .705    .711    .711     .717                                     3   5.000    .715    .719    .718     .724                                     4   3.000    .727    .727    .726     .732                                     5   2.000                                                                               .739                                                                               .000    .736    .735     .742                                     6   1.000    .766                                                                               .760                                                                               .000    .762     .775                                     7   .800     .782    .779                                                                               .784                                                                               .000     .801                                     8   .600     .824    .827    .836                                                                               .848 .000                                     __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf   l                                        __________________________________________________________________________     1   .000 -1.31                                                                              -22.55                                                                             -2.77                                                                              -37.69                                                                             -3.56                                                                              -35.11                                                                             -4.97                                                                               -30.73                                   2   10.000                                                                              -1.07                                                                              -23.17                                                                             -2.54                                                                              -39.67                                                                             -3.33                                                                              -35.87                                                                             -4.75                                                                               -30.82                                   3   5.000                                                                               -.82                                                                               -24.33                                                                             -2.29                                                                              -42.03                                                                             -3.09                                                                              -36.58                                                                             -4.52                                                                               -30.84                                   4   3.000                                                                               -.46                                                                               -26.93                                                                             -1.95                                                                              -45.34                                                                             -2.76                                                                              -37.17                                                                             -4.20                                                                               -30.68                                   5   2.000                                                                               .00 .00 -1.51                                                                              -48.27                                                                             -2.32                                                                              -36.79                                                                             -3.79                                                                               -30.10                                   6   1.000                                                                               1.57                                                                               -43.05                                                                             .00 .00 -.85                                                                               -29.89                                                                             -2.37                                                                               -27.66                                   7   .800 2.47                                                                               -42.62                                                                             .87 -33.91                                                                             .00 .00 -1.56                                                                               -28.02                                   8   .600 4.21                                                                               -36.95                                                                             2.53                                                                               -28.51                                                                             1.62                                                                               -24.83                                                                             .00  .00                                      __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0  = 1.21, K.sub.a      /γ.sub.aR  = 0.84                                                  

                                      TABLE 35                                     __________________________________________________________________________     Conversion Coefficients K.sub.a :(rs), γ.sub.a :(r) Associated with      Direction of Rotation and Correction                                           Coefficient μ:(l) at Telephoto End (77.5 mm) of Third Embodiment            f = 77.5 mm                                                                    __________________________________________________________________________     (R,ANGLE) =                                                                             .000                                                                               .000                                                                               10.000                                                                             .372                                                                               5.000                                                                              .749                                                                               3.000                                                                              1.260                                     Pos R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000 1.621                                                                              .000    1.628   1.632   1.635                                     2   10.000   1.646                                                                              1.651                                                                              .000    1.654   1.656                                     3   5.000    1.668   1.672                                                                              1.673                                                                              .000    1.676                                     4   3.000    1.697   1.700   1.702                                                                              1.706                                                                              .000                                      5   2.000    1.736   1.739   1.741   1.745                                     6   1.000    1.870   1.872   1.874   1.878                                     7   .800     1.950   1.952   1.954   1.957                                     8   .600     2.105   2.107   2.108   2.110                                     __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 .00 .00 -.61                                                                               -44.98                                                                             -1.22                                                                              -50.00                                                                             -2.06                                                                              -50.13                                    2   10.000                                                                              .61 -40.16                                                                             .00 .00 -.62                                                                               -53.99                                                                             -1.47                                                                              -50.58                                    3   5.000                                                                               1.25                                                                               -42.95                                                                             .63 -47.62                                                                             .00 .00 -.86                                                                               -48.97                                    4   3.000                                                                               2.14                                                                               -45.69                                                                             1.51                                                                               -50.36                                                                             .87 -51.82                                                                             .00 .00                                       5   2.000                                                                               3.32                                                                               -46.91                                                                             2.63                                                                               -50.14                                                                             2.03                                                                               -50.32                                                                             1.14                                                                               -49.82                                    6   1.000                                                                               7.44                                                                               -48.46                                                                             6.75                                                                               -50.22                                                                             6.05                                                                               -50.35                                                                             5.10                                                                               -50.57                                    7   .800 9.88                                                                               -48.79                                                                             9.17                                                                               -50.22                                                                             8.44                                                                               -50.35                                                                             7.45                                                                               -50.59                                    8   .600 14.73                                                                              -49.41                                                                             13.96                                                                              -50.55                                                                             13.18                                                                              -50.72                                                                             12.11                                                                              -51.03                                    __________________________________________________________________________     (R,ANGLE) =                                                                             2.000                                                                              1.914                                                                              1.000                                                                              3.977                                                                              .800                                                                               5.069                                                                              .600                                                                               7.000                                     POS R    r   rs  r   rs  r   rs  r   rs                                        __________________________________________________________________________     1   .000     1.640   1.652   1.658   1.665                                     2   10.000   1.660   1.672   1.678   1.685                                     3   5.000    1.681   1.692   1.698   1.705                                     4   3.000    1.710   1.721   1.727   1.733                                     5   2.000                                                                               1.748                                                                              .000    1.759   1.765   1.770                                     6   1.000    1.881                                                                              1.891                                                                              .000    1.897   1.898                                     7   .800     1.960   1.970                                                                              1.974                                                                              .000    1.972                                     8   .600     2.113   2.119   2.119                                                                              2.108                                                                              .000                                      __________________________________________________________________________     POS R    bf  l   bf  l   bf  l   bf  l                                         __________________________________________________________________________     1   .000 -3.14                                                                              -50.86                                                                             -6.57                                                                              -51.87                                                                             -8.40                                                                              -52.40                                                                             -11.66                                                                             -55.44                                    2   10.000                                                                              -2.56                                                                              -51.13                                                                             -6.03                                                                              -51.92                                                                             -7.88                                                                              -52.43                                                                             -11.17                                                                             -55.56                                    3   5.000                                                                               -1.96                                                                              -50.95                                                                             -5.46                                                                              -51.90                                                                             -7.34                                                                              -52.41                                                                             -10.66                                                                             -55.67                                    4   3.000                                                                               -1.12                                                                              -51.92                                                                             -4.67                                                                              -51.96                                                                             -6.58                                                                              -52.44                                                                             -9.95                                                                              -55.87                                    5   2.000                                                                               .00 .00 -3.63                                                                              -51.92                                                                             -5.57                                                                              -52.43                                                                             -9.00                                                                              -56.15                                    6   1.000                                                                               3.88                                                                               -50.86                                                                             .00 .00 -2.07                                                                              -52.56                                                                             -5.74                                                                              -57.63                                    7   .800 6.19                                                                               -50.87                                                                             2.15                                                                               -51.71                                                                             .00 .00 -3.81                                                                              -58.90                                    8   .600 10.75                                                                              -51.43                                                                             6.41                                                                               -53.31                                                                             4.09                                                                               -56.01                                                                             .00 .00                                       __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0  = 1.30, K.sub.a      /γ.sub.aK  = 0.79                                                  

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end, middle position, and telephoto end in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the third embodiment of the present invention are as follows.

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement                                                                       Closest Arrangement                                                K.sub.aO /γ.sub.aO                                                                   K.sub.aK /γ.sub.aK                                  ______________________________________                                         Wide-angle End                                                                            2.75          0.44                                                  (F = 36.0)                                                                     Middle Position                                                                           3.36          0.43                                                  (F = 50.0)                                                                     Telephoto End                                                                             3.80          0.43                                                  (F = 103.0)                                                                    Third embodiment                                                               Wide-angle End                                                                            1.21          0.85                                                  (F = 28.8)                                                                     Middle Position                                                                           1.21          0.84                                                  (F = 50.0)                                                                     Telephoto End                                                                             1.30          0.79                                                  (F = 77.5)                                                                     ______________________________________                                    

As described above, in the third embodiment as well, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced. For this reason, an error of the conversion coefficient K_(a) calculated based on γ_(a) and μ or an error from the actual lens driving amount Δa obtained when only one pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set can be reduced.

Next, in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the third embodiment of the present invention, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                            -4.4%          -13.0%                                               (F = 36.0)                                                                     Middle Position                                                                           -11.8%         -12.0%                                               (F = 50.0)                                                                     Telephoto End                                                                             -12.6%         -14.6%                                               (F = 103.0)                                                                    Third embodiment                                                               Wide-angle End                                                                            -0.2%          -0.5%                                                (F = 28.8)                                                                     Middle Position                                                                           -6.0%          -0.1%                                                (F = 50.0)                                                                     Telephoto End                                                                             -1.2%          -0.1%                                                (F = 77.5)                                                                     ______________________________________                                    

As described above, in the third embodiment as well, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Table 36 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 28) of the third embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

Note that the arrangement of the table and reference symbols are the same as those in the first embodiment. The upper table in Table 36 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.0, 2.0, 1.0, 0.8, and 0.6 m) in the respective zooming states of the focal lengths (F=28.8, 35.0, 50.0, 60.0, 68.0, and 77.5 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and photographing distances.

                                      TABLE 36                                     __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Third Embodiment                                      0.60 m                                                                              0.80 m                                                                              1.00 m                                                                              2.00 m                                                                              3.00 m                                                                              5.00 m                                        __________________________________________________________________________     F 28.800 Bf                                                                            .000 .000 .000 .000 .000 .000                                          F 35.000 Bf                                                                            -.034                                                                               -.029                                                                               -.015                                                                               -.002                                                                               .000 .000                                          F 50.000 Bf                                                                            -.005                                                                               -.015                                                                               -.031                                                                               -.019                                                                               -.007                                                                               -.001                                         F 60.000 Bf                                                                            .007 .021 .021 .001 -.007                                                                               -.009                                         F 68.000 Bf                                                                            .003 .025 .027 .028 .023 .014                                          F 77.500 Bf                                                                            .000 .000 .000 .000 .000 .000                                            ANGLE DA                                                                             7.000                                                                               5.069                                                                               3.977                                                                               1.914                                                                               1.260                                                                               .749                                          F 28.800 DX                                                                            .000 -4.704                                                                              .000 .000 .000 R                                                                              0.60 m                                        F 35.000 DX                                                                            .000 -4.875                                                                              .000 .000 .000 R                                                                              0.60 m                                        F 50.000 DX                                                                            .000 -5.303                                                                              .000 .000 .000 R                                                                              0.60 m                                        F 60.000 DX                                                                            .000 -5.635                                                                              .000 .000 .000 R                                                                              0.60 m                                        F 68.000 DX                                                                            .000 -5.902                                                                              .000 .000 .000 R                                                                              0.60 m                                        F 77.500 DX                                                                            .000 -6.198                                                                              .000 .000 .000 R                                                                              0.60 m                                        F 28.800 DX                                                                            .000 -3.273                                                                              .000 .000 .000 R                                                                              0.80 m                                        F 35.000 DX                                                                            .000 -3.426                                                                              .000 .000 .000 R                                                                              0.80 m                                        F 50.000 DX                                                                            .000 -3.753                                                                              .000 .000 .000 R                                                                              0.80 m                                        F 60.000 DX                                                                            .000 -3.968                                                                              .000 .000 .000 R                                                                              0.80 m                                        F 68.000 DX                                                                            .000 -4.153                                                                              .000 .000 .000 R                                                                              0.80 m                                        F 77.500 DX                                                                            .000 -4.369                                                                              .000 .000 .000 R                                                                              0.80 m                                        F 28.800 DX                                                                            .000 -2.510                                                                              .000 .000 .000 R                                                                              1.00 m                                        F 35.000 DX                                                                            .000 -2.623                                                                              .000 .000 .000 R                                                                              1.00 m                                        F 50.000 DX                                                                            .000 -2.919                                                                              .000 .000 .000 R                                                                              1.00 m                                        F 60.000 DX                                                                            .000 -3.064                                                                              .000 .000 .000 R                                                                              1.00 m                                        F 68.000 DX                                                                            .000 -3.205                                                                              .000 .000 .000 R                                                                              1.00 m                                        F 77.500 DX                                                                            .000 -3.374                                                                              .000 .000 .000 R                                                                              1.00 m                                        F 28.800 DX                                                                            .000 -1.159                                                                              .000 .000 .000 R                                                                              2.00 m                                        F 35.000 DX                                                                            .000 -1.210                                                                              .000 .000 .000 R                                                                              2.00 m                                        F 50.000 DX                                                                            .000 -1.371                                                                              .000 .000 .000 R                                                                              2.00 m                                        F 60.000 DX                                                                            .000 -1.441                                                                              .000 .000 .000 R                                                                              2.00 m                                        F 68.000 DX                                                                            .000 -1.490                                                                              .000 .000 .000 R                                                                              2.00 m                                        F 77.500 DX                                                                            .000 -1.577                                                                              .000 .000 .000 R                                                                              2.00 m                                        F 28.800 DX                                                                            .000 -.753                                                                               .000 .000 .000 R                                                                              3.00 m                                        F 35.000 DX                                                                            .000 -.787                                                                               .000 .000 .000 R                                                                              3.00 m                                        F 50.000 DX                                                                            .000 -.889                                                                               .000 .000 .000 R                                                                              3.00 m                                        F 60.000 DX                                                                            .000 -.947                                                                               .000 .000 .000 R                                                                              3.00 m                                        F 68.000 DX                                                                            .000 -.970                                                                               .000 .000 .000 R                                                                              3.00 m                                        F 77.500 DX                                                                            .000 -1.029                                                                              .000 .000 .000 R                                                                              3.00 m                                        F 28.800 DX                                                                            .000 -.443                                                                               .000 .000 .000 R                                                                              5.00 m                                        F 35.000 DX                                                                            .000 -.463                                                                               .000 .000 .000 R                                                                              5.00 m                                        F 50.000 DX                                                                            .000 -.522                                                                               .000 .000 .000 R                                                                              5.00 m                                        F 60.000 DX                                                                            .000 -.562                                                                               .000 .000 .000 R                                                                              5.00 m                                        F 68.000 DX                                                                            .000 -.572                                                                               .000 .000 .000 R                                                                              5.00 m                                        F 77.500 DX                                                                            .000 -.607                                                                               .000 .000 .000 R                                                                              5.00 m                                        __________________________________________________________________________

As can be seen from Table 36, so-called manual focusing can be attained in the zoom lens according to the third embodiment since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

Fourth Embodiment!

The fourth embodiment is directed to a zoom lens which has a five-unit arrangement, i.e., positive, negative, negative, positive, and negative lens units, and attains focusing by a negative second lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=1.8 m) to the amount of rotation for zooming from the wide-angle end (F=103.0) to the telephoto end (F=243.0) is set to be 1.00.

Table 37 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the fourth embodiment.

The upper table in Table 37 summarizes the focal lengths and principal point interval data of the respective lens units of the optical system corresponding to the fourth embodiment in association with five zooming states (focal length F=103.0 (1-POS), 125.0 (2-POS), 150.0 (3-POS), 200.0 (4-POS), and 243.0 mm (5-POS)).

The middle table in Table 37 summarizes spline sample data when the shape of the focus cam in the second lens unit of the fourth embodiment, which is used for focusing, is expressed by a spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), (4), and (5) correspond to the first, second, third, fourth, and fifth lens units, respectively.

Furthermore, the lower table in Table 37 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=103.0, 125.0, 150.0, 200.0, and 243.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=10.0, 5.0, 3.5, 2.5, 2.0, and 1.8 m) using the focus cam of the fourth embodiment. In this table, since the amount of rotation for zooming from the wide-angle end (F=103.0) to the telephoto end (F =243.0) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=1.8 m) is set to be 10.0, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the fourth embodiment is 1.00.

                                      TABLE 37                                     __________________________________________________________________________     Fourth Embodiment f = 103.0 to 243.0                                           (Rotation Amount Ratio: a.sub.F /a.sub.Z =1.00)                                Focal lengths and Principal Point Intervals of                                 Lens Units of Fourth Embodiment                                                          1-POS                                                                               2-POS                                                                               3-POS                                                                               4-POS                                                                               5-POS                                            __________________________________________________________________________             F 103.0000                                                                            125.0000                                                                            150.0000                                                                            200.0000                                                                            243.0000                                         F1 125.0000                                                                            D1                                                                               10.0000                                                                             16.8348                                                                             23.3339                                                                             34.6511                                                                             43.7903                                          F2 -75.0000                                                                            D2                                                                               15.5000                                                                             16.6157                                                                             17.5514                                                                             18.1101                                                                             17.9136                                          F3 -155.0000                                                                           D3                                                                               42.5955                                                                             34.8159                                                                             27.8141                                                                             18.2438                                                                             13.0161                                          F4 44.0000                                                                             D4                                                                               37.1800                                                                             37.0073                                                                             36.5761                                                                             34.2704                                                                             30.5555                                          F5 -50.0000                                                                            D5                                                                               63.6750                                                                             68.8726                                                                             73.9319                                                                             83.0092                                                                             90.4927                                          __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point)                            Corresponding to Fourth Embodiment                                                 ANGLE                                                                               (1)  (2)  (3)  (4)  (5)                                               __________________________________________________________________________      1  -1.0000                                                                             .0000                                                                               1.6800                                                                              .0000                                                                               .0000                                                                               .0000                                              2  0.0000                                                                              .0000                                                                               0.0000                                                                              .0000                                                                               .0000                                                                               .0000                                              3  1.3835                                                                              .0000                                                                               -2.2358                                                                             .0000                                                                               .0000                                                                               .0000                                              4  2.9178                                                                              .0000                                                                               -4.5825                                                                             .0000                                                                               .0000                                                                               .0000                                              5  4.3714                                                                              .0000                                                                               -6.6902                                                                             .0000                                                                               .0000                                                                               .0000                                              6  6.5399                                                                              .0000                                                                               -9.6519                                                                             .0000                                                                               .0000                                                                               .0000                                              7  8.6886                                                                              .0000                                                                               -12.3998                                                                            .0000                                                                               .0000                                                                               .0000                                              8  10.0000                                                                             .0000                                                                               -13.9954                                                                            .0000                                                                               .0000                                                                               .0000                                              9  11.3835                                                                             .0000                                                                               -15.6208                                                                            .0000                                                                               .0000                                                                               .0000                                             10  12.9178                                                                             .0000                                                                               -17.3576                                                                            .0000                                                                               .0000                                                                               .0000                                             11  14.3714                                                                             .0000                                                                               -18.9438                                                                            .0000                                                                               .0000                                                                               .0000                                             12  16.5399                                                                             .0000                                                                               -21.2145                                                                            .0000                                                                               .0000                                                                               .0000                                             13  18.6886                                                                             .0000                                                                               -23.3638                                                                            .0000                                                                               .0000                                                                               .0000                                             14  20.0000                                                                             .0000                                                                               -24.6304                                                                            .0000                                                                               .0000                                                                               .0000                                             15  21.0000                                                                             .0000                                                                               -25.5750                                                                            .0000                                                                               .0000                                                                               .0000                                             __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation                          for Focusing of Fourth Embodiment                                              (Rotation Amount Ratio: a.sub.F /a.sub.Z = 1.00)                                      Infinity          Amount of                                                    Correspond-                                                                             Photograph-                                                                             Rotation for                                          Focal Length                                                                          ing Position                                                                            ing Distance                                                                            Focusing                                              __________________________________________________________________________     103.0 mm                                                                              .0000    10.00 m  1.383                                                 125.0 mm                                                                              3.0500   5.00 m   2.918                                                 150.0 mm                                                                              5.5500   3.50 m   4.371                                                 200.0 mm                                                                              8.7000   2.50 m   6.540                                                 243.0 mm                                                                              10.0000  2.00 m   8.689                                                                 1.80 m   10.000                                                __________________________________________________________________________     Condition Corresponding Value (1)                                                             1.29 (wide-angle end)                                                                    1.02 (telephoto end)                                  Condition Corresponding Value (2)                                                             0.76                                                            Condition Corresponding Value (3)                                                             1.00                                                            Condition Corresponding Value (4)                                                             0.93 (wide-angle end)                                                                    0.82 (telephoto end)                                  Condition Corresponding Value (5)                                                             0.84 (wide-angle end)                                                                    1.09 (telephoto end)                                  Condition Corresponding Value (6)                                                             1.15 (wide-angle end)                                                                    0.92 (telephoto end)                                  __________________________________________________________________________

Table 38 below summarizes the numerical value data of the cams of the focusing lens unit in the fourth embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 37. Note that the meanings of the reference symbols in Table 38 are the same as those in the first embodiment.

                  TABLE 38                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit                                 in Fourth Embodiment                                                           Focus Cam Numerical Value Data                                                 ANGLE          (2)          F                                                  ______________________________________                                         .0000          .0000        103.0000                                           .5000          -.8217       106.2187                                           1.0000         -1.6279      109.5590                                           1.5000         -2.4188      113.0401                                           2.0000         -3.1949      116.6842                                           2.5000         -3.9566      120.5191                                           3.0000         -4.7046      124.5798                                           3.5000         -5.4395      128.9073                                           4.0000         -6.1617      133.5309                                           4.5000         -6.8717      138.4740                                           5.0000         -7.5700      143.7604                                           5.5000         -8.2571      149.4139                                           6.0000         -8.9334      155.4617                                           6.5000         -9.5992      161.9648                                           7.0000         -10.2552     169.0177                                           7.5000         -10.9014     176.7635                                           8.0000         -11.5381     185.4323                                           8.5000         -12.1655     195.4438                                           9.0000         -12.7839     207.6945                                           9.5000         -13.3937     223.4750                                           10.0000        -13.9954     243.0000                                           10.5000        -14.5895     0.0000                                             11.0000        -15.1760     0.0000                                             11.5000        -15.7551     0.0000                                             12.0000        -16.3268     0.0000                                             12.5000        -16.8913     0.0000                                             13.0000        -17.4488     0.0000                                             13.5000        -17.9996     0.0000                                             14.0000        -18.5438     0.0000                                             14.5000        -19.0816     0.0000                                             15.0000        -19.6134     0.0000                                             15.5000        -20.1392     0.0000                                             16.0000        -20.6592     0.0000                                             16.5000        -21.1737     0.0000                                             17.0000        -21.6827     0.0000                                             17.5000        -22.1865     0.0000                                             18.0000        -22.6852     0.0000                                             18.5000        -23.1789     0.0000                                             19.0000        -23.6677     0.0000                                             19.5000        -24.1517     0.0000                                             20.0000        -24.6304     0.0000                                             ______________________________________                                         Zoom Compensation Cam Numerical Value Data                                     ANGLE          (2)          F                                                  ______________________________________                                         .0000          .0000        103.0000                                           .5000          .5565        106.2187                                           1.0000         1.0970       109.5590                                           1.5000         1.6213       113.0401                                           2.0000         2.1291       116.6842                                           2.5000         2.6204       120.5191                                           3.0000         3.0950       124.5798                                           3.5000         3.5525       128.9073                                           4.0000         3.9928       133.5309                                           4.5000         4.4160       138.4740                                           5.0000         4.8219       143.7604                                           5.5000         5.2103       149.4139                                           6.0000         5.5805       155.4617                                           6.5000         5.9309       161.9648                                           7.0000         6.2582       169.0177                                           7.5000         6.5577       176.7635                                           8.0000         6.8210       185.4323                                           8.5000         7.0330       195.4438                                           9.0000         7.1612       207.6945                                           9.5000         7.1600       223.4750                                           10.0000        7.0228       243.0000                                           ______________________________________                                    

The left table in Table 38 summarizes the numerical value data of the focus cam of the fourth embodiment, and the right table in Table 38 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amounts (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) coincides with the movement locus of the second lens unit calculated using the paraxial data in the upper table in Table 37.

Tables 39, 40, and 41 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(x) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F =103.0), the middle position (F=150.0), and the telephoto end (F=243.0) according to the fourth embodiment, respectively. The arrangements of the respective tables and the meanings of the reference symbols are the same as those in the first embodiment.

                                      TABLE 39                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical                Axis at Wide-angle End (103.0 mm) in Fourth Embodiment                         __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .000                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) -2.236                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.918                                                                              1) .000                                                                             2) -4.583                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) -5.801                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.241                                                                              1) .000                                                                             2) -7.902                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.540                                                                              1) .000                                                                             2) -9.652                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.689                                                                              1) .000                                                                             2) -12.400                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) -13.995                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Wide-angle                 End (103.0 mm) in Fourth Embodiment                                            __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) -.000                                                                            2) -1.875                                                                            3) .401                                                                             4) -.482                                                                            5) 2.274                                     R 10.000                                                                             ANG                                                                               1.383                                                                              1) -.013                                                                            2) -1.905                                                                            3) .401                                                                             4) -.482                                                                            5) 2.274                                     R 5.000                                                                              ANG                                                                               2.918                                                                              1) -.027                                                                            2) -1.936                                                                            3) .401                                                                             4) -.482                                                                            5) 2.274                                     R 4.000                                                                              ANG                                                                               3.749                                                                              1) -.034                                                                            2) -1.952                                                                            3) .401                                                                             4) -.482                                                                            5) 2.274                                     R 3.000                                                                              ANG                                                                               5.241                                                                              1) -.046                                                                            2) -1.980                                                                            3) .401                                                                             4) -.482                                                                            5) 2.274                                     R 2.500                                                                              ANG                                                                               6.540                                                                              1) -.057                                                                            2) -2.004                                                                            3) .401                                                                             4) -.482                                                                            5) 2.274                                     R 2.000                                                                              ANG                                                                               8.689                                                                              1) -.073                                                                            2) -2.040                                                                            3) .401                                                                             4) -.482                                                                            5) 2.274                                     R 1.800                                                                              ANG                                                                               10.000                                                                             1) -.083                                                                            2) -2.062                                                                            3) .401                                                                             4) -.482                                                                            5) 2.274                                     __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction                 of Optical Axis at Wide-angle End (103.0 mm) in Fourth Embodiment              __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -.486                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) -.508                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.918                                                                              1) .000                                                                             2) -.531                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) -.543                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.241                                                                              1) .000                                                                             2) -.564                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.540                                                                              1) .000                                                                             2) -.582                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.689                                                                              1) .000                                                                             2) -.611                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) -.628                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Wide-angle End (103.0 mm)                          in Fourth Embodiment                                                           __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -1.659                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) -1.574                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.918                                                                              1) .000                                                                             2) -1.487                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) -1.444                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.241                                                                              1) .000                                                                             2) -1.375                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.540                                                                              1) .000                                                                             2) -1.320                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.689                                                                              1) .000                                                                             2) -1.239                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) -1.196                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction                 of Rotation at Wide-angle End (103.0 mm) in Fourth Embodiment                  __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .806                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) .799                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.918                                                                              1) .000                                                                             2) .789                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) .784                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.241                                                                              1) .000                                                                             2) .776                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.540                                                                              1) .000                                                                             2) .769                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.689                                                                              1) .000                                                                             2) .757                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) .751                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 1.29,         γ.sub.aR /γ.sub.aO = 0.93                                    

                                      TABLE 40                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical                Axis at Middle Position (150.0 mm) in Fourth Embodiment                        __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .000                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) -1.842                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.917                                                                              1) .000                                                                             2) -3.799                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) -4.824                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.240                                                                              1) .000                                                                             2) -6.606                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.539                                                                              1) .000                                                                             2) -8.102                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.688                                                                              1) .000                                                                             2) -10.476                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) -11.866                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Middle Position            (150.0 mm) in Fourth Embodiment                                                __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -2.813                                                                            3) .338                                                                             4) -.509                                                                            5) 2.479                                     R 10.000                                                                             ANG                                                                               1.383                                                                              1) -.013                                                                            2) -2.837                                                                            3) .338                                                                             4) -.509                                                                            5) 2.479                                     R 5.000                                                                              ANG                                                                               2.917                                                                              1) -.027                                                                            2) -2.863                                                                            3) .338                                                                             4) -.509                                                                            5) 2.479                                     R 4.000                                                                              ANG                                                                               3.749                                                                              1) -.034                                                                            2) -2.877                                                                            3) .338                                                                             4) -.509                                                                            5) 2.479                                     R 3.000                                                                              ANG                                                                               5.240                                                                              1) -.046                                                                            2) -2.901                                                                            3) .338                                                                             4) -.509                                                                            5) 2.479                                     R 2.500                                                                              ANG                                                                               6.539                                                                              1) -.057                                                                            2) -2.921                                                                            3) .338                                                                             4) -.509                                                                            5) 2.479                                     R 2.000                                                                              ANG                                                                               8.688                                                                              1) -.074                                                                            2) -2.952                                                                            3) .338                                                                             4) -.509                                                                            5) 2.479                                     R 1.800                                                                              ANG                                                                               10.000                                                                             1) -.084                                                                            2) -2.971                                                                            3) .338                                                                             4) -.509                                                                            5) 2.479                                     __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction                 of Optical Axis at Middle Position (150.0 mm) in Fourth                        __________________________________________________________________________     Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -1.258                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) -1.283                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.917                                                                              1) .000                                                                             2) -1.310                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) -1.325                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.240                                                                              1) .000                                                                             2) -1.350                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.539                                                                              1) .000                                                                             2) -1.371                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.688                                                                              1) .000                                                                             2) -1.405                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) -1.425                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Middle Position (150.0 mm)                         in Fourth Embodiment                                                           __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -1.361                                                                           3) .000                                                                             4) .000                                                                             5) .000                                       R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) -1.305                                                                           3) .000                                                                             4) .000                                                                             5) .000                                       R 5.000                                                                              ANG                                                                               2.917                                                                              1) .000                                                                             2) -1.247                                                                           3) .000                                                                             4) .000                                                                             5) .000                                       R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) -1.218                                                                           3) .000                                                                             4) .000                                                                             5) .000                                       R 3.000                                                                              ANG                                                                               5.240                                                                              1) .000                                                                             2) -1.172                                                                           3) .000                                                                             4) .000                                                                             5) .000                                       R 2.500                                                                              ANG                                                                               6.539                                                                              1) .000                                                                             2) -1.134                                                                           3) .000                                                                             4) .000                                                                             5) .000                                       R 2.000                                                                              ANG                                                                               8.688                                                                              1) .000                                                                             2) -1.076                                                                           3) .000                                                                             4) .000                                                                             5) .000                                       R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) -1.045                                                                           3) .000                                                                             4) .000                                                                             5) .000                                       __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction                 of Rotation at Middle Position (150.0 mm) in Fourth Embodiment                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 1.712                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) 1.674                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.917                                                                              1) .000                                                                             2) 1.634                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) 1.613                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.240                                                                              1) .000                                                                             2) 1.582                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.539                                                                              1) .000                                                                             2) 1.554                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.688                                                                              1) .000                                                                             2) 1.511                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) 1.488                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 1.13,         γ.sub.aR /γ.sub.aO = 0.87                                    

                                      TABLE 41                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical                Axis at Telephoto End (243.0 mm) in Fourth Embodiment                          __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) .000                                                                              3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) -1.625                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.918                                                                              1) .000                                                                             2) -3.362                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) -4.276                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.241                                                                              1) .000                                                                             2) -5.872                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.540                                                                              1) .000                                                                             2) -7.219                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.689                                                                              1) .000                                                                             2) -9.368                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) -10.635                                                                           3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Telephoto End              (243.0 mm) in Fourth Embodiment                                                __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -12.078                                                                           3) .134                                                                             4) -.426                                                                            5) 2.810                                     R 10.000                                                                             ANG                                                                               1.383                                                                              1) -.013                                                                            2) -12.100                                                                           3) .134                                                                             4) -.426                                                                            5) 2.810                                     R 5.000                                                                              ANG                                                                               2.918                                                                              1) -.027                                                                            2) -12.123                                                                           3) .134                                                                             4) -.426                                                                            5) 2.810                                     R 4.000                                                                              ANG                                                                               3.749                                                                              1) -.034                                                                            2) -12.135                                                                           3) .134                                                                             4) -.426                                                                            5) 2.810                                     R 3.000                                                                              ANG                                                                               5.241                                                                              1) -.047                                                                            2) -12.156                                                                           3) .134                                                                             4) -.426                                                                            5) 2.810                                     R 2.500                                                                              ANG                                                                               6.540                                                                              1) -.057                                                                            2) -12.174                                                                           3) .134                                                                             4) -.426                                                                            5) 2.810                                     R 2.000                                                                              ANG                                                                               8.689                                                                              1) -.074                                                                            2) -12.203                                                                           3) .134                                                                             4) -.426                                                                            5) 2.810                                     R 1.800                                                                              ANG                                                                               10.000                                                                             1) -.085                                                                            2) -12.220                                                                           3) .134                                                                             4) -.426                                                                            5) 2.810                                     __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction                 of Optical Axis at Telephoto End (243.0 mm) in Fourth Embodiment               __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -3.753                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) -3.767                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.918                                                                              1) .000                                                                             2) -3.781                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) -3.789                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.241                                                                              1) .000                                                                             2) -3.802                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.540                                                                              1) .000                                                                             2) -3.814                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.689                                                                              1) .000                                                                             2) -3.832                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) -3.842                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Telephoto End (243.0 mm)                           in Fourth Embodiment                                                           __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) -1.196                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) -1.154                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.918                                                                              1) .000                                                                             2) -1.110                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) -1.088                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.241                                                                              1) .000                                                                             2) -1.052                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.540                                                                              1) .000                                                                             2) -1.023                                                                            3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.689                                                                              1) .000                                                                             2) -.979                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) -.952                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction                 of Rotation at Telephoto End (243.0 mm) in Fourth Embodiment                   __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1) .000                                                                             2) 4.488                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 10.000                                                                             ANG                                                                               1.383                                                                              1) .000                                                                             2) 4.348                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 5.000                                                                              ANG                                                                               2.918                                                                              1) .000                                                                             2) 4.199                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 4.000                                                                              ANG                                                                               3.749                                                                              1) .000                                                                             2) 4.124                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 3.000                                                                              ANG                                                                               5.241                                                                              1) .000                                                                             2) 3.999                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.500                                                                              ANG                                                                               6.540                                                                              1) .000                                                                             2) 3.900                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 2.000                                                                              ANG                                                                               8.689                                                                              1) .000                                                                             2) 3.751                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      R 1.800                                                                              ANG                                                                               10.000                                                                             1) .000                                                                             2) 3.658                                                                             3) .000                                                                             4) .000                                                                             5) .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.xO = 1.02,         γ.sub.aR /γ.sub.aO = 0.82                                    

As can be seen from Tables 39, 40, and 41, at each focal length, the conversion coefficient YX associated with the direction of the optical axis increases but the value of the slope (dx/da) of the focus cam decreases as the photographing distance becomes closer to the closest distance. Therefore, as can be seen from these tables, the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, decreases as the photographing distance becomes closer to the closest distance by the influence of the slope (dx/da) of the focus cam. From Tables 39, 40, and 41, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×0.93 at the wide-angle end (F =103.0), ×0.87 at the middle position (F=150.0), and ×0.82 at the telephoto end (F=243.0). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the fourth embodiment is calculated using formula (a), and is compared with that in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values:

Embodiment of Japanese Patent Application

Laid-Open No. 5-142475

    N.sub.W >9.3 N.sub.M >10.1 N.sub.T >8.1

Fourth Embodiment

    N.sub.W >0.4 N.sub.M >0.8 N.sub.T >1.1

Therefore, as can be seen from a comparison with the embodiment of Japanese Patent Application Laid-Open No. 5-142475 ), the values of the numbers N of divisions become very small.

As described above, in the fourth embodiment as well, since the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation is much smaller than that in the conventional system, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Tables 42, 43, and 44 summarize the calculation results of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=103.0), middle position (F=150.0), and telephoto end (F=243.0) according to the fourth embodiment. The arrangements of the tables and reference symbols are the same as those in the first embodiment. The position of the focusing lens in the first pair in the upper two tables in each of Tables 42, 43, and 44, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Tables 42, 43, and 44, i.e., in the ninth and tenth columns is (R, ANGLE)=(1.8, 10.0), and it indicates that this position corresponds to the closest in-focus (R=1.8 m) corresponding position.

                                      TABLE 42                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of                                                              Rotation and Correction Coefficient μ: (l) at Wide-angle End                (103.0 mm) of Fourth Embodiment                                                f = 103.0 mm                                                                   (R,ANGLE) =                                                                            .000                                                                               .000                                                                               10.000                                                                             1.383                                                                              5.000                                                                              2.918                                                                              4.000                                                                              3.749                                      POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000                                                                               .806                                                                               .000    .820    .832    .838                                       2   10.000  .785                                                                               .799                                                                               .000    .811    .817                                       3   5.000   .763    .777                                                                               .789                                                                               .000    .796                                       4   4.000   .752    .765    .778                                                                               .784                                                                               .000                                       5   3.000   .732    .746    .759    .765                                       6   2.500   .716    .730    .743    .750                                       7   2.000   .692    .706    .719    .726                                       8   1.800   .678    .692    .706    .712                                       __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               .00 .00 -1.13                                                                              43.33                                                                              -2.43                                                                              44.37                                                                              -3.14                                                                              45.41                                      2   10.000                                                                             1.09                                                                               42.53                                                                              .00 .00 -1.24                                                                              44.46                                                                              -1.93                                                                              45.55                                      3   5.000                                                                              2.23                                                                               41.92                                                                              1.19                                                                               42.38                                                                              .00 .00 -.66                                                                               45.06                                      4   4.000                                                                              2.82                                                                               41.90                                                                              1.81                                                                               42.75                                                                              .65 45.71                                                                              .00 .00                                        5   3.000                                                                              3.84                                                                               42.00                                                                              2.88                                                                               43.22                                                                              1.76                                                                               45.90                                                                              1.14                                                                               47.74                                      6   2.500                                                                              4.69                                                                               42.18                                                                              3.76                                                                               43.59                                                                              2.69                                                                               46.24                                                                              2.09                                                                               47.87                                      7   2.000                                                                              6.01                                                                               42.56                                                                              5.16                                                                               44.19                                                                              4.15                                                                               46.84                                                                              3.59                                                                               48.39                                      8   1.800                                                                              6.78                                                                               42.79                                                                              5.96                                                                               44.50                                                                              5.00                                                                               47.13                                                                              4.45                                                                               48.64                                      __________________________________________________________________________     (R,ANGLE) =                                                                            3.000                                                                              5.241                                                                              2.500                                                                              6.540                                                                              2.000                                                                              8.689                                                                              1.800                                                                              10.000                                     POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000    .848    .854    .863    .867                                       2   10.000  .827    .834    .844    .848                                       3   5.000   .805    .813    .823    .828                                       4   4.000   .794    .802    .813    .818                                       5   3.000                                                                              .776                                                                               .000    .784    .795    .800                                       6   2.500   .760                                                                               .769                                                                               .000    .780    .786                                       7   2.000   .737    .745                                                                               .756                                                                               .000    .763                                       8   1.800   .723    .732    .744                                                                               .751                                                                               .000                                       __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               -4.44                                                                              47.80                                                                              -5.59                                                                              50.38                                                                              -7.50                                                                              52.92                                                                              -8.67                                                                              56.09                                      2   10.000                                                                             -3.19                                                                              48.14                                                                              -4.30                                                                              50.94                                                                              -6.16                                                                              53.31                                                                              -7.31                                                                              56.72                                      3   5.000                                                                              -1.87                                                                              48.52                                                                              -2.94                                                                              51.71                                                                              -4.75                                                                              53.70                                                                              -5.86                                                                              57.47                                      4   4.000                                                                              -1.19                                                                              48.70                                                                              -2.24                                                                              52.25                                                                              -4.01                                                                              53.86                                                                              -5.11                                                                              57.90                                      5   3.000                                                                              .00 .00 -1.02                                                                              53.91                                                                              -2.74                                                                              53.89                                                                              -3.81                                                                              58.74                                      6   2.500                                                                              .99 50.63                                                                              .00 .00 -1.68                                                                              53.30                                                                              -2.72                                                                              59.66                                      7   2.000                                                                              2.54                                                                               50.99                                                                              1.60                                                                               51.86                                                                              .00 .00 -1.00                                                                              64.81                                      8   1.800                                                                              3.44                                                                               51.16                                                                              2.53                                                                               52.36                                                                              .98 59.69                                                                              .00 .00                                        __________________________________________________________________________      Condition Corresponding Values: K.sub.aO /γ.sub.aO = 0.84, K.sub.aR      /γ.sub.aR = 1.15                                                   

                                      TABLE 43                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of                                                              Rotation and Correction Coefficient μ: (l) at Middle Position               (150.0 mm) of Fourth Embodiment                                                f = 150.0 mm                                                                   (R,ANGLE) =                                                                            .000                                                                               .000                                                                               10.000                                                                             1.383                                                                              5.000                                                                              2.917                                                                              4.000                                                                              3.749                                      POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000                                                                               1.712                                                                              .000    1.702   1.688   1.679                                      2   10.000  1.683                                                                              1.675                                                                              .000    1.662   1.654                                      3   5.000   1.653   1.645                                                                              1.633                                                                              .000    1.627                                      4   4.000   1.637   1.630   1.619                                                                              1.614                                                                              .000                                       5   3.000   1.610   1.604   1.596   1.591                                      6   2.500   1.588   1.583   1.577   1.572                                      7   2.000   1.553   1.551   1.546   1.542                                      8   1.800   1.534   1.532   1.528   1.525                                      __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               .00 .00 -2.35                                                                              150.48                                                                             -4.92                                                                              147.42                                                                             -6.30                                                                              156.52                                     2   10.000                                                                             2.33                                                                               137.97                                                                             .00 .00 -2.55                                                                              145.91                                                                             -3.91                                                                              159.45                                     3   5.000                                                                              4.82                                                                               139.24                                                                             2.52                                                                               139.37                                                                             .00 .00 -1.35                                                                              173.60                                     4   4.000                                                                              6.14                                                                               139.63                                                                             3.86                                                                               141.54                                                                             1.35                                                                               158.58                                                                             .00 .00                                        5   3.000                                                                              8.44                                                                               141.39                                                                             6.19                                                                               145.75                                                                             3.71                                                                               162.02                                                                             2.37                                                                               163.49                                     6   2.500                                                                              10.38                                                                              143.18                                                                             8.16                                                                               148.79                                                                             5.71                                                                               164.35                                                                             4.39                                                                               168.03                                     7   2.000                                                                              13.50                                                                              145.70                                                                             11.33                                                                              152.29                                                                             8.92                                                                               166.44                                                                             7.62                                                                               170.67                                     8   1.800                                                                              15.34                                                                              147.20                                                                             13.20                                                                              154.21                                                                             10.82                                                                              167.95                                                                             9.53                                                                               172.49                                     __________________________________________________________________________     (R,ANGLE) =                                                                            3.000                                                                              5.240                                                                              2.500                                                                              6.539                                                                              2.000                                                                              8.688                                                                              1.800                                                                              10.000                                     POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000    1.664   1.649   1.623   1.607                                      2   10.000  1.640   1.627   1.603   1.587                                      3   5.000   1.615   1.603   1.581   1.567                                      4   4.000   1.602   1.591   1.570   1.557                                      5   3.000                                                                              1.583                                                                              .000    1.571   1.552   1.539                                      6   2.500   1.563                                                                              1.553                                                                              .000    1.536   1.524                                      7   2.000   1.535   1.527                                                                              1.508                                                                              .000    1.501                                      8   1.800   1.519   1.511   1.498                                                                              1.498                                                                              .000                                       __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               -8.72                                                                              171.50                                                                             -10.78                                                                             174.27                                                                             -14.10                                                                             185.14                                                                             -16.06                                                                             203.49                                     2   10.000                                                                             -6.33                                                                              176.62                                                                             -8.39                                                                              176.86                                                                             -11.71                                                                             187.04                                                                             -13.68                                                                             207.35                                     3   5.000                                                                              -3.75                                                                              187.27                                                                             -5.81                                                                              179.69                                                                             -9.13                                                                              188.48                                                                             -11.10                                                                             211.82                                     4   4.000                                                                              -2.39                                                                              196.67                                                                             -4.44                                                                              179.61                                                                             -7.76                                                                              188.18                                                                             -9.73                                                                              213.90                                     5   3.000                                                                              .00 .00 -2.04                                                                              173.73                                                                             -5.35                                                                              185.73                                                                             -7.32                                                                              218.10                                     6   2.500                                                                              2.03                                                                               163.51                                                                             .00 .00 -3.30                                                                              180.64                                                                             -5.27                                                                              224.00                                     7   2.000                                                                              5.29                                                                               173.79                                                                             3.28                                                                               194.02                                                                             .00 .00 -1.97                                                                              241.89                                     8   1.800                                                                              7.23                                                                               177.59                                                                             5.23                                                                               195.44                                                                             1.96                                                                               276.31                                                                             .00 .00                                        __________________________________________________________________________      Condition Corresponding Values: K.sub.aO /γ.sub.aO = 0.90, K.sub.aR      /γ.sub.aR = 1.08                                                   

                                      TABLE 44                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of                                                              Rotation and Correction Coefficient μ: (l) at Telephoto End                 (243.0 mm) of Fourth Embodiment                                                f = 243.0 mm                                                                   (R,ANGLE) =                                                                            .000                                                                               .000                                                                               10.000                                                                             1.383                                                                              5.000                                                                              2.918                                                                              4.000                                                                              3.749                                      POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000                                                                               4.492                                                                              .000    4.299   4.103   4.003                                      2   10.000  4.540                                                                              4.350                                                                              .000    4.147   4.046                                      3   5.000   4.598   4.402                                                                              4.197                                                                              .000    4.096                                      4   4.000   4.631   4.433   4.228                                                                              4.127                                                                              .000                                       5   3.000   4.693   4.491   4.283   4.178                                      6   2.500   4.750   4.545   4.334   4.227                                      7   2.000   4.851   4.641   4.425   4.316                                      8   1.800   4.917   4.703   4.484   4.372                                      __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               .00 .00 -5.95                                                                              -509.72                                                                            -11.97                                                                             -532.49                                                                            -15.01                                                                             -500.78                                    2   10.000                                                                             6.28                                                                               -583.37                                                                            .00 .00 -6.36                                                                              -533.78                                                                            -9.57                                                                              -488.95                                    3   5.000                                                                              13.42                                                                              -566.63                                                                            6.75                                                                               -570.88                                                                            .00 .00 -3.40                                                                              -459.09                                    4   4.000                                                                              17.36                                                                              -560.34                                                                            10.49                                                                              -552.98                                                                            3.51                                                                               -482.50                                                                            .00 .00                                        5   3.000                                                                              24.59                                                                              -550.13                                                                            17.32                                                                              -535.08                                                                            9.95                                                                               -486.43                                                                            6.23                                                                               -501.67                                    6   2.500                                                                              31.06                                                                              -541.39                                                                            23.44                                                                              -523.36                                                                            15.70                                                                              -481.31                                                                            11.80                                                                              -482.87                                    7   2.000                                                                              42.15                                                                              -527.29                                                                            33.90                                                                              -506.98                                                                            25.54                                                                              -470.59                                                                            21.32                                                                              -465.42                                    8   1.800                                                                              49.17                                                                              -519.92                                                                            40.53                                                                              -499.25                                                                            31.76                                                                              -465.46                                                                            27.33                                                                              -459.02                                    __________________________________________________________________________     (R,ANGLE) =                                                                            3.000                                                                              5.241                                                                              2.500                                                                              6.540                                                                              2.000                                                                              8.689                                                                              1.800                                                                              10.000                                     POS R   r   rs  r   rs  r   rs  r   rs                                         __________________________________________________________________________     1   .000    3.833   3.696   3.487   3.369                                      2   10.000  3.874   3.735   3.523   3.404                                      3   5.000   3.921   3.780   3.565   3.445                                      4   4.000   3.948   3.806   3.590   3.468                                      5   3.000                                                                              3.996                                                                              .000    3.855   3.635   3.511                                      6   2.500   4.046                                                                              3.906                                                                              .000    3.677   3.551                                      7   2.000   4.130   3.980                                                                              3.757                                                                              .000    3.619                                      8   1.800   4.183   4.030   3.796                                                                              3.664                                                                              .000                                       __________________________________________________________________________     POS R   bf  l   bf  l   bf  l   bf  l                                          __________________________________________________________________________     1   .000                                                                               -20.09                                                                             -493.32                                                                            -24.17                                                                             -448.91                                                                            -30.30                                                                             -422.05                                                                            -33.69                                                                             -418.33                                    2   10.000                                                                             -14.94                                                                             -488.94                                                                            -19.26                                                                             -438.63                                                                            -25.74                                                                             -414.07                                                                            -29.33                                                                             -412.56                                    3   5.000                                                                              -9.11                                                                              -487.95                                                                            -13.69                                                                             -424.47                                                                            -20.58                                                                             -404.56                                                                            -24.39                                                                             -406.48                                    4   4.000                                                                              -5.89                                                                              -493.88                                                                            -10.62                                                                             -414.22                                                                            -17.73                                                                             -398.97                                                                            -21.68                                                                             -403.44                                    5   3.000                                                                              .00 .00 -5.01                                                                              -380.66                                                                            -12.53                                                                             -387.49                                                                            -16.71                                                                             -398.76                                    6   2.500                                                                              5.26                                                                               -417.13                                                                            .00 .00 -7.90                                                                              -372.94                                                                            -12.29                                                                             -395.67                                    7   2.000                                                                              14.24                                                                              -424.66                                                                            8.55                                                                               -454.22                                                                            .00 .00 -4.75                                                                              -385.25                                    8   1.800                                                                              19.91                                                                              -424.55                                                                            13.94                                                                              -439.01                                                                            4.98                                                                               -478.16                                                                            .00 .00                                        __________________________________________________________________________      Condition Corresponding Values: K.sub.aO /γ.sub.aO = 1.09, K.sub.aR      /γ.sub.aR = 0.92                                                   

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end, middle position, and telephoto end in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the fourth embodiment of the present invention are as follows.

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement                                                                       Closest Arrangement                                                K.sub.aO /γ.sub.aO                                                                   K.sub.aK /γ.sub.aK                                  ______________________________________                                         Wide-angle End                                                                            2.75          0.44                                                  (F = 36.0)                                                                     Middle Position                                                                           3.36          0.43                                                  (F = 50.0)                                                                     Telephoto End                                                                             3.80          0.43                                                  (F = 103.0)                                                                    Fourth Embodiment                                                              Wide-angle End                                                                            0.84          1.15                                                  (F = 103.0)                                                                    Middle Position                                                                           0.90          1.08                                                  (F = 150.0)                                                                    Telephoto End                                                                             1.09          1.92                                                  (F = 243.0)                                                                    ______________________________________                                    

As described above, in the fourth embodiment as well, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced. For this reason, an error of the conversion coefficient K_(a) calculated based on γ_(a) and μ or an error from the actual lens driving amount Δa obtained when only one pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set can be reduced.

Next, in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the fourth embodiment of the present invention, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                            -4.4%          -13.0%                                               (F = 36.0)                                                                     Middle Position                                                                           -11.8%         -12.0%                                               (F = 50.0)                                                                     Telephoto End                                                                             -12.6%         -14.6%                                               (F = 103.0)                                                                    Fourth Embodiment                                                              Wide-angle End                                                                            0.3%           0.4%                                                 (F = 103.0)                                                                    Middle Position                                                                           0.5%           0.3%                                                 (F = 150.0)                                                                    Telephoto End                                                                             0.5%           0.3%                                                 (F = 243.0)                                                                    ______________________________________                                    

As described above, in the fourth embodiment as well, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Table 45 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 37) of the fourth embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

Note that the arrangement of the table and reference symbols are the same as those in the first embodiment. The upper table in Table 45 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=10.0, 5.0, 3.5, 2.5, 2.0, and 1.8 m) in the respective zooming states of the focal lengths (F=103.0, 125.0, 150.0, 200.0, and 243.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and photographing distances.

                                      TABLE 45                                     __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Fourth Embodiment                                     1.80 m                                                                              2.00 m                                                                              2.50 m                                                                              3.50 m                                                                              5.00 m                                                                              10.00 m                                       __________________________________________________________________________     F 103.000 Bf                                                                           .000 .000 .000 .000 .000 .000                                          F 125.000 Bf                                                                           .000 -.001                                                                               -.002                                                                               -.003                                                                               -.003                                                                               -.002                                         F 150.000 Bf                                                                           .000 -.001                                                                               -.002                                                                               .000 -.001                                                                               -.001                                         F 200.000 Bf                                                                           -.015                                                                               -.008                                                                               -.003                                                                               .001 .004 .005                                          F 243.000 Bf                                                                           .000 .000 .000 .000 .000 .000                                            ANGLE DA                                                                             10.000                                                                              8.689                                                                               6.540                                                                               4.371                                                                               2.918                                                                               1.383                                         F 103.000 DX                                                                           .000 -13.995                                                                             .000 .000 R                                                                              1.80 m                                             F 125.000 DX                                                                           .000 -12.725                                                                             .000 .000 R                                                                              1.80 m                                             F 150.000 DX                                                                           .000 -11.866                                                                             .000 .000 R                                                                              1.80 m                                             F 200.000 DX                                                                           .000 -10.961                                                                             .000 .000 R                                                                              1.80 m                                             F 243.000 DX                                                                           .000 -10.635                                                                             .000 .000 R                                                                              1.80 m                                             F 103.000 DX                                                                           .000 -12.400                                                                             .000 .000 R                                                                              2.00 m                                             F 125.000 DX                                                                           .000 -11.250                                                                             .000 .000 R                                                                              2.00 m                                             F 150.000 DX                                                                           .000 -10.476                                                                             .000 .000 R                                                                              2.00 m                                             F 200.000 DX                                                                           .000 -9.661                                                                              .000 .000 R                                                                              2.00 m                                             F 243.000 DX                                                                           .000 -9.368                                                                              .000 .000 R                                                                              2.00 m                                             F 103.000 DX                                                                           .000 -9.652                                                                              .000 .000 R                                                                              2.50 m                                             F 125.000 DX                                                                           .000 -8.724                                                                              .000 .000 R                                                                              2.50 m                                             F 150.000 DX                                                                           .000 -8.104                                                                              .000 .000 R                                                                              2.50 m                                             F 200.000 DX                                                                           .000 -7.452                                                                              .000 .000 R                                                                              2.50 m                                             F 243.000 DX                                                                           .000 -7.219                                                                              .000 .000 R                                                                              2.50 m                                             F 103.000 DX                                                                           .000 -6.690                                                                              .000 .000 R                                                                              3.50 m                                             F 125.000 DX                                                                           .000 -6.022                                                                              .000 .000 R                                                                              3.50 m                                             F 150.000 DX                                                                           .000 -5.576                                                                              .000 .000 R                                                                              3.50 m                                             F 200.000 DX                                                                           .000 -5.114                                                                              .000 .000 R                                                                              3.50 m                                             F 243.000 DX                                                                           .000 -4.948                                                                              .000 .000 R                                                                              3.50 m                                             F 103.000 DX                                                                           .000 -4.583                                                                              .000 .000 R                                                                              5.00 m                                             F 125.000 DX                                                                           .000 -4.111                                                                              .000 .000 R                                                                              5.00 m                                             F 150.000 DX                                                                           .000 -3.800                                                                              .000 .000 R                                                                              5.00 m                                             F 200.000 DX                                                                           .000 -3.477                                                                              .000 .000 R                                                                              5.00 m                                             F 243.000 DX                                                                           .000 -3.362                                                                              .000 .000 R                                                                              5.00 m                                             F 103.000 DX                                                                           .000 -2.236                                                                              .000 .000 R                                                                              10.00 m                                            F 125.000 DX                                                                           .000 -1.999                                                                              .000 .000 R                                                                              10.00 m                                            F 150.000 DX                                                                           .000 -1.843                                                                              .000 .000 R                                                                              10.00 m                                            F 200.000 DX                                                                           .000 -1.681                                                                              .000 .000 R                                                                              10.00 m                                            F 243.000 DX                                                                           .000 -1.625                                                                              .000 .000 R                                                                              10.00 m                                            __________________________________________________________________________

As can be seen from Table 45, in the zoom lens of the fourth embodiment, so-called manual focusing can be attained since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

Fifth Embodiment!

The fifth embodiment is directed to a zoom lens which has a five-unit arrangement, i.e., positive, negative, negative, positive, and positive lens units, and attains focusing by a negative second lens unit. In this zoom lens, the rotation amount ratio (a_(F) /a_(Z)) of the rotation amount for focusing from the infinity in-focus position to the closest in-focus position (R=1.5 m) to the amount of rotation for zooming from the wide-angle end (F=81.5) to the telephoto end (F=196.0) is set to be 1.50.

Table 46 below summarizes various paraxial data of an optical system and data for defining the shape of a focus cam according to the fifth embodiment.

The upper table in Table 46 summarizes the focal lengths and principal point interval data of the respective lens units of the optical system corresponding to the fifth embodiment in association with five zooming states (focal length F=81.5 (1-POS), 105.0 (2-POS), 135.0 (3-POS), 150.0 (4-POS), and 196.0 mm (5-POS)).

The middle table in Table 46 summarizes spline sample data when the shape of the focus cam in the second lens unit of the fifth embodiment, which is used for focusing, is expressed by a spline function associated with the angle a of rotation of a rotatable lens barrel and the amount x of movement in the direction of the optical axis. In this middle table, (1), (2), (3), (4), and (5) correspond to the first, second, third, fourth, and fifth lens units, respectively.

Furthermore, the lower table in Table 46 summarizes the infinity focusing positions (infinity corresponding positions) at the respective focal lengths (F=81.5, 105.0, 135.0, 150.0, and 196.0 mm), and the amounts of rotation (amounts of rotation for focusing) upon focusing to respective photographing distances (R=5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m) using the focus cam of the fifth embodiment. In this table, since the amount of rotation for zooming from the wide-angle end (F=81.5) to the telephoto end (F=196.0) is set to be 10.0, and the amount of rotation for focusing from the infinity in-focus position to the closest in-focus position (R=1.5 m) is set to be 15.0, the rotation amount ratio (a_(F) /a_(Z)) of the amount of rotation for focusing to the amount of rotation for zooming in the fifth embodiment is 1.50.

                                      TABLE 46                                     __________________________________________________________________________     Fifth Embodiment f = 81.5 to 196.0 (Rotation Amount Ratio: a.sub.p             /a.sub.z = 1.50)                                                               __________________________________________________________________________     Focal lengths and Principal Point Intervals of Lens Units of Fifth             embodiment                                                                                1-POS                                                                               2-POS 3-POS                                                                               4-POS 5-POS                                         __________________________________________________________________________             F  81.5000                                                                             105.0000                                                                             135.0000                                                                            150.0000                                                                             196.0000                                      F1 126.0000                                                                            D1 14.7057                                                                             28.4458                                                                              39.0422                                                                             42.7524                                                                               50.5918                                      F2 -115.0000                                                                           D2 29.0000                                                                             29.0000                                                                              29.0000                                                                             29.0000                                                                               29.0000                                      F3 -59.0000                                                                            D3 32.7254                                                                             27.4883                                                                              20.8004                                                                             17.4555                                                                               7.1940                                       F4 93.0000                                                                             D4 13.8546                                                                              5.3516                                                                               1.4431                                                                              1.0778                                                                               3.4999                                       F5 110.0000                                                                            DS 110.3381                                                                            110.3381                                                                             110.3381                                                                            110.3381                                                                             110.3381                                      __________________________________________________________________________     Focus Cam Shape (Spline Interpolation Sample Point) Corresponding to           Fifth Embodiment                                                                    ANGLE (1)  (2)    (3)  (4)  (5)                                           __________________________________________________________________________     1    -10.0000                                                                             .0000                                                                               7.9609 .0000                                                                               .0000                                                                               .0000                                         2    .0000 .0000                                                                               0.0000 .0000                                                                               .0000                                                                               .0000                                         3    4.0460                                                                               .0000                                                                               -3.4006                                                                               .0000                                                                               .0000                                                                               .0000                                         4    5.8885                                                                               .0000                                                                               -5.0081                                                                               .0000                                                                               .0000                                                                               .0000                                         5    8.4545                                                                               .0000                                                                               -7.3123                                                                               .0000                                                                               .0000                                                                               .0000                                         6    10.0000                                                                              .0000                                                                               -8.7391                                                                               .0000                                                                               .0000                                                                               .0000                                         7    10.8153                                                                              .0000                                                                               -9.4973                                                                               .0000                                                                               .0000                                                                               .0000                                         8    12.9878                                                                              .0000                                                                               -11.5719                                                                              .0000                                                                               .0000                                                                               .0000                                         9    14.0460                                                                              0000 -12.5991                                                                              .0000                                                                               .0000                                                                               .0000                                         10   15.0000                                                                              .0000                                                                               -13.5443                                                                              .0000                                                                               .0000                                                                               .0000                                         11   15.8885                                                                              .0000                                                                               -14.4279                                                                              .0000                                                                               .0000                                                                               .0000                                         12   18.4545                                                                              .0000                                                                               -17.0546                                                                              .0000                                                                               .0000                                                                               .0000                                         13   20.0000                                                                              .0000                                                                               -18.6840                                                                              .0000                                                                               .0000                                                                               .0000                                         14   20.8153                                                                              0000 -19.5509                                                                              .0000                                                                               .0000                                                                               .0000                                         15   22.9878                                                                              .0000                                                                               -21.9262                                                                              .0000                                                                               .0000                                                                               .0000                                         16   25.0000                                                                              .0000                                                                               -24.1894                                                                              .0000                                                                               .0000                                                                               .0000                                         __________________________________________________________________________     Amount of Rotation for Zooming and Amount of Rotation for Focusing of          Fifth Embodiment                                                               (Rotation Amount Ratio: a.sub.p /a.sub.z = 1.50)                                      Infinity              Amount of                                         Focal Length                                                                          Corresponding Position                                                                    Photographing Distance                                                                    Rotation for Focusing                             __________________________________________________________________________      81.5 mm                                                                               .0000     5.00 m     4.046                                             105.0 mm                                                                              1.9000     3.50 m     5.889                                             135.0 mm                                                                              4.7000     2.50 m     8.455                                             150.0 mm                                                                              6.3000     2.00 m     10.815                                            196.0 mm                                                                              10.0000    1.70 m     12.988                                                              1.50 m     15.000                                            __________________________________________________________________________     Condition Corresponding Value (1)                                                               0.99 (wide-angle end)                                                                      0.90 (telephoto end)                              Condition Corresponding Value (2)                                                               1.14                                                          Condition Corresponding Value (3)                                                               1.50                                                          Condition Corresponding Value (4)                                                               1.20 (wide-angle end)                                                                      1.09 (telephoto end)                              Condition Corresponding Value (5)                                                               0.97 (wide-angle end)                                                                      1.11 (telephoto end                               Condition Corresponding Value (6)                                                               1.03 (wide-angle end)                                                                      0.90 (telephoto end)                              __________________________________________________________________________

Table 47 below summarizes the numerical value data of the cams of the focusing lens unit in the fifth embodiment, which data are calculated by interpolation based on a spline function on the basis of the sample data of the focus cam summarized in the middle table in Table 46. Note that the meanings of the reference symbols in Table 47 are the same as those in the first embodiment.

                  TABLE 47                                                         ______________________________________                                         Cam Numerical Value Data of Focusing Lens Unit in Fifth Embodiment                               Zoom Compensation Cam                                        Focus Cam Numerical Value Data                                                                   Numerical Value Data                                         ANGLE  (2)      F         ANGLE (2)     F                                      ______________________________________                                         .0000  .0000    81.5000   .0000 .0000   81.5000                                .5000  -.4119   87.4335   .5000 -3.7531 87.4335                                1.0000 -.8260   93.7130   1.0000                                                                               -7.1735 93.7130                                1.5000 -1.2422  100.0226  1.5000                                                                               -10.1258                                                                               100.0226                               2.0000 -1.6608  106.2314  2.0000                                                                               -12.6318                                                                               106.2314                               2.5000 -2.0818  112.2353  2.5000                                                                               -14.7316                                                                               112.2353                               3.0000 -2.5054  117.9014  3.0000                                                                               -16.4517                                                                               117.9014                               3.5000 -2.9318  123.2332  3.5000                                                                               -17.8628                                                                               123.2332                               4.0000 -3.3610  128.2864  4.0000                                                                               -19.0342                                                                               128.2864                               4.5000 -3.7931  133.1182  4.5000                                                                               -20.0189                                                                               133.1182                               5.0000 -4.2281  137.7829  5.0000                                                                               -20.8577                                                                               137.7829                               5.5000 -4.6660  142.3980  5.5000                                                                               -21.5980                                                                               142.3980                               6.0000 -5.1065  147.0960  6.0000                                                                               -22.2809                                                                               147.0960                               6.5000 -5.5498  151.9853  6.5000                                                                               -22.9332                                                                               151.9853                               7.0000 -5.9959  157.1399  7.0000                                                                               -23.5682                                                                               157.1399                               7.5000 -6.4452  162.5968  7.5000                                                                               -24.1889                                                                               162.5968                               8.0000 -6.8978  168.3947  8.0000                                                                               -24.7972                                                                               168.3947                               8.5000 -7.3540  174.5777  8.5000                                                                               -25.3948                                                                               174.5777                               9.0000 -7.8137  181.1974  9.0000                                                                               -25.9837                                                                               181.1974                               9.5000 -8.2759  188.3144  9.5000                                                                               -26.5667                                                                               188.3144                               10.0000                                                                               -8.7391  196.0000  10.0000                                                                              -27.1470                                                                               196.0000                               10.5000                                                                               -9.2030  .0000                                                          11.0000                                                                               -9.6707  .0000                                                          11.5000                                                                               -10.1438 .0000                                                          12.0000                                                                               -10.6212 .0000                                                          12.5000                                                                               -11.1016 .0000                                                          13.0000                                                                               -11.5836 .0000                                                          13.5000                                                                               -12.0668 .0000                                                          14.0000                                                                               -12.5539 .0000                                                          14.5000                                                                               -13.0475 .0000                                                          15.0000                                                                               -13.5443 .0000                                                          15.5000                                                                               -14.0409 .0000                                                          16.0000                                                                               -14.5395 .0000                                                          16.5000                                                                               15.0429  .0000                                                          17.0000                                                                               15.5511  .0000                                                          17.5000                                                                               -16.0638 .0000                                                          18.0000                                                                               -16.5810 .0000                                                          18.5000                                                                               -17.1022 .0000                                                          19.0000                                                                               -17.6272 .0000                                                          19.5000                                                                               -18.1548 .0000                                                          20.0000                                                                               -18.6840 .0000                                                          20.5000                                                                               -19.2145 .0000                                                          21.0000                                                                               -19.7489 .0000                                                          21.5000                                                                               -20.2889 .0000                                                          22.0000                                                                               -20.8344 .0000                                                          22.5000                                                                               -21.3848 .0000                                                          23.0000                                                                               -21.9397 .0000                                                          23.5000                                                                               -22.4986 .0000                                                          24.0000                                                                               -23.0605 .0000                                                          24.5000                                                                               -23.6244 .0000                                                          25.0000                                                                               -24.1894 .0000                                                          ______________________________________                                    

The left table in Table 47 summarizes the numerical value data of the focus cam of the fifth embodiment, and the right table in Table 47 summarizes the numerical value data of the zoom compensation cam of this embodiment. A value obtained by synthesizing the amounts (2) of movement in the direction of the optical axis in the numerical value data of the focus cam and the zoom compensation cam in the range from the amount of rotation (ANGLE=0.0) to the amount of rotation (ANGLE=10.0) coincides with the movement locus of the second lens unit calculated using the paraxial data in the upper table in Table 46.

Tables 48, 49, and 50 below summarize the amount DX (mm) of movement for focusing, in the direction of the optical axis, of the focusing lens unit, the imaging magnifications β_(x) of the respective lens units, the conversion coefficient γ_(x) associated with the direction of the optical axis, the slope (dx/da) of the focus cam, and the conversion coefficient γ_(a) associated with the direction of rotation at the wide-angle end (F=81.5), the middle position (F=135.0), and the telephoto end (F=196.0) according to the fifth embodiment, respectively. The arrangements of the respective tables and the meanings of the reference symbols are the same as those in the first embodiment.

                                      TABLE 48                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Wide-angle                                                                     End (81.5 mm) in Fifth Embodiment                                              __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               .000                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.979                                                                              1)                                                                               .000                                                                              2)                                                                               -1.643                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5;)                                                                              .000                                      R 5.000                                                                              AND                                                                               4.046                                                                              1)                                                                               .000                                                                              2)                                                                               -3.401                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.889                                                                              1)                                                                               .000                                                                              2)                                                                               -5.008                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.455                                                                              1)                                                                               .000                                                                              2)                                                                               -7.312                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.815                                                                             1)                                                                               .000                                                                              2)                                                                               -9.497                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5;)                                                                              .000                                      R 1.700                                                                              ANG                                                                               12.988                                                                             1)                                                                               .000                                                                              2)                                                                               -11.572                                                                            3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.000                                                                             1)                                                                               .000                                                                              2)                                                                               -13.544                                                                            3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Wide-angle End (81.5       mm) in Fifth Embodiment                                                        __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               31.033                                                                             3)                                                                               -.018                                                                             4)                                                                               386.84                                                                             5)                                                                               -.003                                     R 10.000                                                                             ANG                                                                               1.979                                                                              1)                                                                               -.013                                                                             2)                                                                               31.019                                                                             3)                                                                               -.018                                                                             4)                                                                               386.84                                                                             5)                                                                               -.003                                     R 5.000                                                                              ANG                                                                               4.046                                                                              1)                                                                               -.027                                                                             2)                                                                               31.003                                                                             3)                                                                               -.018                                                                             4)                                                                               386.84                                                                             5)                                                                               -.003                                     R 3.500                                                                              ANG                                                                               5.889                                                                              1)                                                                               -.040                                                                             2)                                                                               30.989                                                                             3)                                                                               -.018                                                                             4)                                                                               386.84                                                                             5)                                                                               -.003                                     R 2.500                                                                              ANG                                                                               8.455                                                                              1)                                                                               -.058                                                                             2)                                                                               30.969                                                                             3)                                                                               -.018                                                                             4)                                                                               386.84                                                                             5)                                                                               -.003                                     R 2.000                                                                              ANG                                                                               10.815                                                                             1)                                                                               -.075                                                                             2)                                                                               30.950                                                                             3)                                                                               -.018                                                                             4)                                                                               386.84                                                                             5)                                                                               -.003                                     R 1.700                                                                              ANG                                                                               12.988                                                                             1)                                                                               -.092                                                                             2)                                                                               30.932                                                                             3)                                                                               -.018                                                                             4)                                                                               386.84                                                                             5)                                                                               -.003                                     R 1.500                                                                              ANG                                                                               15.000                                                                             1)                                                                               -.107                                                                             2)                                                                               30.915                                                                             3)                                                                               -.018                                                                             4)                                                                               386.84                                                                             5)                                                                               -.003                                     __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Wide-angle End                                                         (81.5 mm) in Fifth Embodiment                                                  __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               -.418                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.979                                                                              1)                                                                               .000                                                                              2)                                                                               -.418                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.046                                                                              1)                                                                               .000                                                                              2)                                                                               -.417                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.889                                                                              1)                                                                               .000                                                                              2)                                                                               -.417                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.455                                                                              1)                                                                               .000                                                                              2)                                                                               -.416                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.815                                                                             1)                                                                               .000                                                                              2)                                                                               -.416                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               12.988                                                                             1)                                                                               .000                                                                              2)                                                                               -.415                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.000                                                                             1)                                                                               .000                                                                              2)                                                                               -.415                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Wide-angle End (81.5 mm) in Fifth                  __________________________________________________________________________     Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               -.822                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.979                                                                              1)                                                                               .000                                                                              2)                                                                               -.839                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.046                                                                              1)                                                                               .000                                                                              2)                                                                               -.862                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.889                                                                              1)                                                                               .000                                                                              2)                                                                               -.883                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.455                                                                              1)                                                                               .000                                                                              2)                                                                               -.916                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.815                                                                             1)                                                                               .000                                                                              2)                                                                               -.937                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               12.988                                                                             1)                                                                               .000                                                                              2)                                                                               -.965                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.000                                                                             1)                                                                               .000                                                                              2)                                                                               -.994                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Wide-angle End                                                     (81.5 mm) in Fifth Embodiment                                                  __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               .344                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.979                                                                              1)                                                                               .000                                                                              2)                                                                               .350                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.046                                                                              1)                                                                               .000                                                                              2)                                                                               .360                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.889                                                                              1)                                                                               .000                                                                              2)                                                                               .368                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.455                                                                              1)                                                                               .000                                                                              2)                                                                               .381                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.815                                                                             1)                                                                               .000                                                                              2)                                                                               .389                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               12.988                                                                             1)                                                                               .000                                                                              2)                                                                               .401                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.000                                                                             1)                                                                               .000                                                                              2)                                                                               .412                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 0.99,         γ.sub.aR /γ.sub.a0 = 1.20                                    

                                      TABLE 49                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Middle Position                                                                (135.0 mm) in Fifth Embodiment                                                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               .000                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.982                                                                              1)                                                                               .000                                                                              2)                                                                               -1.745                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.047                                                                              1)                                                                               .000                                                                              2)                                                                               -3.614                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.893                                                                              1)                                                                               .000                                                                              2)                                                                               -5.323                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.464                                                                              1)                                                                               .000                                                                              2)                                                                               -7.775                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.827                                                                             1)                                                                               .000                                                                              2)                                                                               -10.101                                                                            3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               13.008                                                                             1)                                                                               .000                                                                              2)                                                                               -12.312                                                                            3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.014                                                                             1)                                                                               .000                                                                              2)                                                                               -14.414                                                                            3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Middle Position            (135.0 mm) in Fifth Embodiment                                                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               4.101                                                                              3)                                                                               -.220                                                                             4)                                                                               386.98                                                                             5)                                                                               -.003                                     R 10.000                                                                             ANG                                                                               1.982                                                                              1)                                                                               -.013                                                                             2)                                                                               4.086                                                                              3)                                                                               -.220                                                                             4)                                                                               386.98                                                                             5)                                                                               -.003                                     R 5.000                                                                              ANG                                                                               4.047                                                                              1)                                                                               -.027                                                                             2)                                                                               4.070                                                                              3)                                                                               -.220                                                                             4)                                                                               386.98                                                                             5)                                                                               -.003                                     R 3.500                                                                              ANG                                                                               5.893                                                                              1)                                                                               -.040                                                                             2)                                                                               4.055                                                                              3)                                                                               -.220                                                                             4)                                                                               386.98                                                                             5)                                                                               -.003                                     R 2.500                                                                              ANG                                                                               8.464                                                                              1)                                                                               -.058                                                                             2)                                                                               4.033                                                                              3)                                                                               -.220                                                                             4)                                                                               386.98                                                                             5)                                                                               -.003                                     R 2.000                                                                              ANG                                                                               10.827                                                                             1)                                                                               -.075                                                                             2)                                                                               4.013                                                                              3)                                                                               -.220                                                                             4)                                                                               386.98                                                                             5)                                                                               -.003                                     R 1.700                                                                              ANG                                                                               13.008                                                                             1)                                                                               -.092                                                                             2)                                                                               3.994                                                                              3)                                                                               -.220                                                                             4)                                                                               386.98                                                                             5)                                                                               -.003                                     R 1.500                                                                              ANG                                                                               15.014                                                                             1)                                                                               -.107                                                                             2)                                                                               3.976                                                                              3)                                                                               -.220                                                                             4)                                                                               386.98                                                                             5)                                                                               -.003                                     Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Middle Position                                                        (135.0 mm) in Fifth Embodiment                                                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               -1.080                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.982                                                                              1)                                                                               .000                                                                              2)                                                                               -1.071                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.047                                                                              1)                                                                               .000                                                                              2)                                                                               -1.062                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.893                                                                              1)                                                                               .000                                                                              2)                                                                               -1.054                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.464                                                                              1)                                                                               .000                                                                              2)                                                                               -1.042                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.827                                                                             1)                                                                               .000                                                                              2)                                                                               -1.031                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               13.008                                                                             1)                                                                               .000                                                                              2)                                                                               -1.021                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.014                                                                             1)                                                                               .000                                                                              2)                                                                               -1.011                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Middle Position (135.0 mm) in Fifth                __________________________________________________________________________     Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               -.870                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.982                                                                              1)                                                                               .000                                                                              2)                                                                               -.891                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.047                                                                              1)                                                                               .000                                                                              2)                                                                               -.920                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.893                                                                              1)                                                                               .000                                                                              2)                                                                               -.932                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.464                                                                              1)                                                                               .000                                                                              2)                                                                               -.965                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.827                                                                             1)                                                                               .000                                                                              2)                                                                               -.994                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               13.008                                                                             1)                                                                               .000                                                                              2)                                                                               -1.034                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.014                                                                             1)                                                                               .000                                                                              2)                                                                               -1.058                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Middle Position                                                    (135.0 mm) in Fifth Embodiment                                                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               .939                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.982                                                                              1)                                                                               .000                                                                              2)                                                                               .955                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.047                                                                              1)                                                                               .000                                                                              2)                                                                               .977                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.893                                                                              1)                                                                               .000                                                                              2)                                                                               .982                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.464                                                                              1)                                                                               .000                                                                              2)                                                                               1.006                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.827                                                                             1)                                                                               .000                                                                              2)                                                                               1.025                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               13.008                                                                             1)                                                                               .000                                                                              2)                                                                               1.055                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.014                                                                             1)                                                                               .000                                                                              2)                                                                               1.070                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.xR /γ.sub.x0 = 0.94,         γ.sub.aR /γ.sub.a0 = 1.14                                    

                                      TABLE 50                                     __________________________________________________________________________     Amount DX (mm) of Movement for Focusing in Direction of Optical Axis at        Telephoto End                                                                  (196.0 mm) in Fifth Embodiment                                                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               .000                                                                               3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.980                                                                              1)                                                                               .000                                                                              2)                                                                               -1.863                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.046                                                                              1)                                                                               .000                                                                              2)                                                                               -3.860                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.889                                                                              1)                                                                               .000                                                                              2)                                                                               -5.689                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.455                                                                              1)                                                                               .000                                                                              2)                                                                               -8.316                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               1.815                                                                              1)                                                                               .000                                                                              2)                                                                               -10.812                                                                            3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               12.988                                                                             1)                                                                               .000                                                                              2)                                                                               -13.187                                                                            3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.000                                                                             1)                                                                               .000                                                                              2)                                                                               -15.450                                                                            3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________     Imaging Magnification β.sub.K of Lens Units at Telephoto End (196.0       mm) in Fifth Embodiment                                                        __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               2.905                                                                              3)                                                                               -.450                                                                             4)                                                                               386.95                                                                             5)                                                                               -.003                                     R 10.000                                                                             ANG                                                                               1.980                                                                              1)                                                                               -.013                                                                             2)                                                                               2.888                                                                              3)                                                                               -.450                                                                             4)                                                                               386.95                                                                             5)                                                                               -.003                                     R 5.000                                                                              ANG                                                                               4.046                                                                              1)                                                                               -.027                                                                             2)                                                                               2.871                                                                              3)                                                                               -.450                                                                             4)                                                                               386.95                                                                             5)                                                                               -.003                                     R 3.500                                                                              ANG                                                                               5.889                                                                              1)                                                                               -.040                                                                             2)                                                                               2.855                                                                              3)                                                                               -.450                                                                             4)                                                                               386.95                                                                             5)                                                                               -.003                                     R 2.500                                                                              ANG                                                                               8.445                                                                              1)                                                                               -.058                                                                             2)                                                                               2.832                                                                              3)                                                                               -.450                                                                             4)                                                                               386.95                                                                             5)                                                                               -.003                                     R 2.000                                                                              ANG                                                                               10.815                                                                             1)                                                                               -.075                                                                             2)                                                                               2.811                                                                              3)                                                                               -.450                                                                             4)                                                                               386.95                                                                             5)                                                                               -.003                                     R 1.700                                                                              ANG                                                                               12.988                                                                             1)                                                                               -.092                                                                             2)                                                                               2.790                                                                              3)                                                                               -.450                                                                             4)                                                                               386.95                                                                             5)                                                                               -.003                                     R 1.500                                                                              ANG                                                                               15.000                                                                             1)                                                                               -.107                                                                             2)                                                                               2.770                                                                              3)                                                                               -.450                                                                             4)                                                                               386.95                                                                             5)                                                                               -.003                                     __________________________________________________________________________     Conversion Coefficient γ.sub.x Associated With Direction of Optical      Axis at Telephoto End                                                          (196.0 mm) in Fifth Embodiment                                                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               -2.133                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.980                                                                              1)                                                                               .000                                                                              2)                                                                               -2.106                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.046                                                                              1)                                                                               .000                                                                              2)                                                                               -2.077                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.889                                                                              1)                                                                               .000                                                                              2)                                                                               -2.051                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.445                                                                              1)                                                                               .000                                                                              2)                                                                               -2.014                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.815                                                                             1)                                                                               .000                                                                              2)                                                                               -1.979                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               12.988                                                                             1)                                                                               .000                                                                              2)                                                                               -1.946                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.000                                                                             1)                                                                               .000                                                                              2)                                                                               -1.914                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________     Slope dx/da of Focus Cam at Telephoto End (196.0 mm) in Fifth                  __________________________________________________________________________     Embodiment                                                                     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               -.927                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.980                                                                              1)                                                                               .000                                                                              2)                                                                               -.958                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.046                                                                              1)                                                                               .000                                                                              2)                                                                               -.982                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.889                                                                              1)                                                                               .000                                                                              2)                                                                               -.999                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.455                                                                              1)                                                                               .000                                                                              2)                                                                               -1.046                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.815                                                                             1)                                                                               .000                                                                              2)                                                                               -1.070                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               12.988                                                                             1)                                                                               .000                                                                              2)                                                                               -1.114                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.000                                                                             1)                                                                               .000                                                                              2)                                                                               -1.130                                                                             3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________     Conversion Coefficient γ.sub.a Associated With Direction of              Rotation at Telephoto End                                                      (196.0 mm) in Fifth Embodiment                                                 __________________________________________________________________________     R .000                                                                               ANG                                                                               .000                                                                               1)                                                                               .000                                                                              2)                                                                               1.977                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 10.000                                                                             ANG                                                                               1.980                                                                              1)                                                                               .000                                                                              2)                                                                               2.018                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 5.000                                                                              ANG                                                                               4.046                                                                              1)                                                                               .000                                                                              2)                                                                               2.040                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 3.500                                                                              ANG                                                                               5.889                                                                              1)                                                                               .000                                                                              2)                                                                               2.050                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.500                                                                              ANG                                                                               8.455                                                                              1)                                                                               .000                                                                              2)                                                                               2.106                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 2.000                                                                              ANG                                                                               10.815                                                                             1)                                                                               .000                                                                              2)                                                                               2.117                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.700                                                                              ANG                                                                               12.988                                                                             1)                                                                               .000                                                                              2)                                                                               2.167                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      R 1.500                                                                              ANG                                                                               15.000                                                                             1)                                                                               .000                                                                              2)                                                                               2.164                                                                              3)                                                                               .000                                                                              4)                                                                               .000                                                                               5)                                                                               .000                                      __________________________________________________________________________      Condition Corresponding Values: γ.sub.aR /γ.sub.a0 =               γ.sub.aR /γ.sub.a0 = 1.09                                    

As can be seen from Tables 48, 49, and 50, at each focal length, the conversion coefficient YX associated with the direction of the optical axis decreases but the value of the slope (dx/da) of the focus cam increases as the photographing distance becomes closer to the closest distance. Therefore, as can be seen from these tables, the value of the conversion coefficient γ_(a) associated with the direction of rotation, which is defined as the product of the conversion coefficient γ_(x) and the slope (dx/da) of the focus cam, increases as the photographing distance becomes closer to the closest distance by the influence of the slope (dx/da) of the focus cam. From Tables 48, 49, and 50, the rate of change, from the infinity in-focus position to the closest in-focus position, of the conversion coefficient γ_(a) associated with the direction of rotation is ×1.2 at the wide-angle end (F =81.5), ×1.14 at the middle position (F=135.0), and ×1.09 at the telephoto end (F=196.0). When the number N of divisions of the focus range upon a change in conversion coefficient γ_(a) in the fifth embodiment is calculated using formula (a), and is compared with that in the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the numbers N_(W), N_(M), and N_(T) of divisions at the wide-angle end, middle position, and telephoto end respectively have the following values:

Embodiment of Japanese Patent Application Laid-Open No. 5-142475

    N.sub.W >9.3 N.sub.M >10.1 N.sub.T >8.1

Fifth Embodiment

    N.sub.W >1.0 N.sub.M >0.7 N.sub.T >0.5

Therefore, as can be seen from a comparison with the embodiment of Japanese Patent Application Laid-Open No. 5-142475, the values of the numbers N of divisions become very small.

As described above, in the fifth embodiment as well, since the rate of change of the conversion coefficient γ_(a) associated with the direction of rotation is much smaller than that in the conventional system, the values of the numbers N of divisions become small. For this reason, the number of data of the conversion coefficient γ_(a) and the correction coefficient μ can be reduced, and the storage capacity can be suppressed.

Table 51, 52, and 53 summarize the calculation results of the conversion coefficient K_(a) and the correction coefficient μ at the wide-angle end (F=81.5), middle position (F=135.0), and telephoto end (F=196.0) according to the fifth embodiment. The arrangements of the tables and reference symbols are the same as those in the first embodiment. The position of the focusing lens in the first pair in the upper two tables in each of Table 51, 52, and 53, i.e., in the third and fourth columns is (R, ANGLE)=(0.0, 0.0), and it indicates that this position corresponds to the infinity corresponding position. Similarly, the position of the focusing lens in the fourth pair in the lower two tables in each of Table 51, 52, and 53, i.e., in the ninth and tenth columns is (R, ANGLE)=(1.5, 15.0), and it indicates that this position corresponds to the closest in-focus (R=1.5 m) corresponding position.

                                      TABLE 51                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Wide-angle End (81.5 mm) of Fifth Embodiment          f = 81.5 mm                                                                    __________________________________________________________________________     (R,ANGLE) =                                                                            .000                                                                               .000                                                                               10.000                                                                             1.979                                                                               5.000                                                                             4.046                                                                              3.500                                                                              5.889                                      POS R   r   rs  r   rs   r  rs  r   rs                                         __________________________________________________________________________     1   .000                                                                               .344                                                                               .000    .352    .362    .372                                       2   10.000  .342                                                                               .350                                                                               .000    .361    .370                                       3   5.000   .340    .349 .360                                                                              .000    .369                                       4   3.500   .339    .348    .358                                                                               .368                                                                               .000                                       5   2.500   .337    .347    .357    .366                                       6   2.000   .336    .345    .355    .364                                       7   1.700   .335    .344    .354    .363                                       8   1.500   .333    .342    .352    .362                                       __________________________________________________________________________     POS R   bf  l   bf  l    bf l   bf  l                                          __________________________________________________________________________     1   .000                                                                               .00 .00 -.70                                                                               132.74                                                                              -1.47                                                                             188.92                                                                             -2.19                                                                              200.28                                     2   10.000                                                                             .68 113.45                                                                             .00 .00  -.75                                                                              224.87                                                                             -1.45                                                                              211.38                                     3   5.000                                                                              1.38                                                                               131.67                                                                             .72 191.71                                                                              .00                                                                               .00 -.68                                                                               192.62                                     4   3.500                                                                              2.00                                                                               146.14                                                                             1.36                                                                               205.58                                                                              .66                                                                               229.49                                                                             .00 .00                                        5   2.500                                                                              2.85                                                                               158.58                                                                             2.24                                                                               207.53                                                                              1.57                                                                              217.15                                                                             .94 231.24                                     6   2.000                                                                              3.63                                                                               161.99                                                                             3.05                                                                               198.62                                                                              2.40                                                                              199.02                                                                             1.80                                                                               193.80                                     7   1.700                                                                              4.35                                                                               166.05                                                                             3.78                                                                               197.93                                                                              3.16                                                                              198.74                                                                             2.58                                                                               196.87                                     8   1.500                                                                              5.00                                                                               167.44                                                                             4.46                                                                               194.86                                                                              3.86                                                                              195.02                                                                             3.29                                                                               193.22                                     __________________________________________________________________________     (R,ANGLE) =                                                                            2.500                                                                              8.455                                                                              2.000                                                                              10.815                                                                              1.700                                                                             12.988                                                                             1.500                                                                              15.000                                     POS R   r   rs  r   rs   r  rs  r   rs                                         __________________________________________________________________________     1   .000    .386    .399    .412    .424                                       2   10.000  .384    .398    .410    .423                                       3   5.000   .383    .396    .409    .421                                       4   3.500   .382    .395    .408    .420                                       5   2.500                                                                              .381                                                                               .000    .392    .405    .417                                       6   2.000   .378                                                                               .389                                                                               .000    .404    .416                                       7   1.700   .376    .390 .401                                                                              .000    .414                                       8   1.500   .375    .388    .400                                                                               .412                                                                               .000                                       __________________________________________________________________________     POS R   bf  l   bf  l    bf l   bf  l                                          __________________________________________________________________________     1   .000                                                                               -3.26                                                                              257.39                                                                             -4.32                                                                              172.39                                                                              -5.35                                                                             186.59                                                                             -6.37                                                                              213.46                                     2   10.000                                                                             -2.49                                                                              283.67                                                                             -3.51                                                                              166.86                                                                              -4.52                                                                             182.74                                                                             -5.50                                                                              212.81                                     3   5.000                                                                              -1.69                                                                              317.52                                                                             -2.68                                                                              155.05                                                                              -3.66                                                                             174.68                                                                             -4.61                                                                              209.61                                     4   3.500                                                                              -.98                                                                               464.78                                                                             -1.94                                                                              141.92                                                                              -2.89                                                                             166.47                                                                             -3.82                                                                              207.65                                     5   2.500                                                                              .00 .00 -.93                                                                               117.45                                                                              -1.84                                                                             152.10                                                                             -2.73                                                                              208.11                                     6   2.000                                                                              .89 100.32                                                                             .00 .00  -.88                                                                              104.77                                                                             -1.74                                                                              195.50                                     7   1.700                                                                              1.71                                                                               139.79                                                                             .85 -1057.0                                                                             .00                                                                               .00 -.83                                                                               212.46                                     8   1.500                                                                              2.45                                                                               151.57                                                                             1.62                                                                               430.24                                                                              .81                                                                               668.05                                                                             .00 .00                                        __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.97, H.sub.aR      /γ.sub.aR = 1.03                                                   

                                      TABLE 52                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Middle Position (135.0 mm) of Fifth Embodiment        f = 135.0 mm                                                                   __________________________________________________________________________     (R,ANGLE) =                                                                           .000                                                                               .000 10.000                                                                             1.982                                                                               5.000                                                                              4.047                                                                               3.500                                                                              5.893                                    POS                                                                               R   r   rs   r   rs   r   rs   r   rs                                       __________________________________________________________________________     1  .000                                                                               .939                                                                               .000     .956     .974     .989                                     2  10.000  .938 .955                                                                               .000     .974     .989                                     3  5.000   .938     .956 .977                                                                               .000     .988                                     4  3.500   .937     .955     .971 .982                                                                               .000                                     5  2.500   .936     .954     .971     .988                                     6  2.000   .935     .953     .971     .987                                     7  1.700   .934     .952     .970     .987                                     8  1.500   .934     .952     .970     .987                                     __________________________________________________________________________     POS                                                                               R   bf  l    bf  l    bf  l    bf  l                                        __________________________________________________________________________     1  .000                                                                               .00 .00  -1.89                                                                              2760.49                                                                             -3.94                                                                              -1365.1                                                                             -5.83                                                                              823.13                                   2  10.000                                                                             1.86                                                                               2018.35                                                                             .00 .00  -2.01                                                                              -845.65                                                                             -3.87                                                                              546.21                                   3  5.000                                                                              3.80                                                                               5243.70                                                                             1.97                                                                               -1352.9                                                                             .00 .00  -1.82                                                                              328.67                                   4  3.500                                                                              5.52                                                                               2971.35                                                                             3.73                                                                               16382.9                                                                             1.79                                                                               320.65                                                                              .00 .00                                      5  2.500                                                                              7.93                                                                               2877.23                                                                             6.18                                                                               5996.77                                                                             4.29                                                                               787.33                                                                              2.54                                                                               -412.38                                  6  2.000                                                                              10.13                                                                              2641.01                                                                             8.43                                                                               4138.32                                                                             6.58                                                                               1069.71                                                                             4.87                                                                               -914.86                                  7  1.700                                                                              12.16                                                                              2471.36                                                                             10.50                                                                              3462.65                                                                             8.69                                                                               1253.91                                                                             7.02                                                                               -1533.7                                  8  1.500                                                                              14.03                                                                              2710.70                                                                             12.41                                                                              4040.62                                                                             10.64                                                                              1607.26                                                                             9.00                                                                               -1732.1                                  __________________________________________________________________________     (R,ANGLE) =                                                                           2.500                                                                              8.464                                                                               2.000                                                                              10.827                                                                              1.700                                                                              13.008                                                                              1.500                                                                              15.014                                   POS                                                                               R   r   rs   r   rs   r   rs   r   rs                                       __________________________________________________________________________     1  .000    1.011    1.030    1.048    1.064                                    2  10.000  1.011    1.031    1.048    1.065                                    3  5.000   1.010    1.030    1.048    1.066                                    4  3.500   1.011    1.031    1.049    1.067                                    5  2.500                                                                              1.006                                                                              .000     1.031    1.049    1.068                                    6  2.000   1.010                                                                               1.025                                                                              .000     1.049    1.069                                    7  1.700   1.009    1.030                                                                               1.055                                                                              .000     1.073                                    8  1.500   1.011    1.033    1.056                                                                               1.070                                                                              .000                                     __________________________________________________________________________     POS                                                                               R   bf  l    bf  l    bf  l    bf  l                                        __________________________________________________________________________     1  .000                                                                               -8.55                                                                              1860.39                                                                             -11.15                                                                             2147.74                                                                             13.63                                                                              -2075.9                                                                             -15.98                                                                             -3179.6                                  2  10.000                                                                             -6.55                                                                              1375.16                                                                             -9.12                                                                              1649.79                                                                             -11.56                                                                             -1911.2                                                                             -13.88                                                                             -3323.7                                  3  5.000                                                                              -4.46                                                                              1058.62                                                                             -6.99                                                                              1307.68                                                                             -9.40                                                                              -1583.3                                                                             -11.69                                                                             -3236.8                                  4  3.500                                                                              -2.60                                                                              553.10                                                                              -5.09                                                                              883.51                                                                              -7.46                                                                              -1375.9                                                                             -9.73                                                                              -3580.0                                  5  2.500                                                                              .00 .00  -2.44                                                                              441.09                                                                              -4.77                                                                              -896.09                                                                             -7.00                                                                              -3972.9                                  6  2.000                                                                              2.39                                                                               -662.15                                                                             .00 .00  -2.29                                                                              -439.90                                                                             -4.48                                                                              -14477.                                  7  1.700                                                                              4.59                                                                               -1460.1                                                                             2.25                                                                               -439.43                                                                             .00 .00  -2.15                                                                              679.70                                   8  1.500                                                                              6.62                                                                               -1459.9                                                                             4.32                                                                               -553.59                                                                             2.12                                                                               -2356.5                                                                             .00 .00                                      __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 0.99, K.sub.aR      /γ.sub.aR = 0.99                                                   

                                      TABLE 53                                     __________________________________________________________________________     Conversion Coefficients K.sub.a : (rs), γ.sub.a : (r) Associated         with Direction of Rotation and Correction                                      Coefficient μ: (l) at Telephoto End (196.0 mm) of Fifth Embodiment          f = 196.0 mm                                                                   __________________________________________________________________________     (R,ANGLE) =                                                                           .000                                                                               .000 10.000                                                                             1.980                                                                               5.000                                                                              4.046                                                                               3.500                                                                              5.889                                    POS                                                                               R   r   rs   r   rs   r   rs   r   rs                                       __________________________________________________________________________     1  .000                                                                               1.977                                                                              .000     1.981    1.979    1.977                                    2  10.000  2.007                                                                               2.017                                                                              .000     2.007    2.005                                    3  5.000   2.035    2.036                                                                               2.040                                                                              .000     2.035                                    4  3.500   2.061    2.063    2.063                                                                               2.050                                                                              .000                                     5  2.500   2.099    2.101    2.102    2.102                                    6  2.000   2.134    2.136    2.138    2.137                                    7  1.700   2.167    2.171    2.173    2.173                                    8  1.500   2.199    2.203    2.205    2.206                                    __________________________________________________________________________     POS                                                                               R   bf  l    bf  l    bf  l    bf  l                                        __________________________________________________________________________     1  .000                                                                               .00 .00  -3.92                                                                              -215.72                                                                             -8.01                                                                              -269.02                                                                             -11.64                                                                             -326.58                                  2  10.000                                                                             3.97                                                                               -258.63                                                                             .00 .00  -4.15                                                                              -252.87                                                                             -7.83                                                                              -354.07                                  3  5.000                                                                              8.24                                                                               -277.39                                                                             4.21                                                                               -447.18                                                                             .00 .00  -3.75                                                                              -495.01                                  4  3.500                                                                              12.14                                                                              -283.29                                                                             8.06                                                                               -357.60                                                                             3.80                                                                               -337.95                                                                             .00 .00                                      5  2.500                                                                              17.75                                                                              -286.85                                                                             13.60                                                                              -327.38                                                                             9.27                                                                               -304.45                                                                             5.39                                                                               -213.17                                  6  2.000                                                                              23.08                                                                              -290.65                                                                             18.88                                                                              -320.14                                                                             14.47                                                                              -302.76                                                                             10.53                                                                              -247.64                                  7  1.700                                                                              28.15                                                                              -291.92                                                                             23.89                                                                              -314.51                                                                             19.43                                                                              -299.08                                                                             15.43                                                                              -257.41                                  8  1.500                                                                              32.98                                                                              -293.52                                                                             28.68                                                                              -312.19                                                                             24.16                                                                              -298.45                                                                             20.10                                                                              -264.29                                  __________________________________________________________________________     (R,ANGLE) =                                                                           2.500                                                                              8.455                                                                               2.000                                                                              10.815                                                                              1.700                                                                              12.988                                                                              1.500                                                                              15.000                                   POS                                                                               R   r   rs   r   rs   r   rs   r   rs                                       __________________________________________________________________________     1  .000    1.972    1.963    1.954    1.943                                    2  10.000  2.000    1.992    1.983    1.972                                    3  5.000   2.030    2.022    2.014    2.003                                    4  3.500   2.059    2.050    2.042    2.032                                    5  2.500                                                                              2.106                                                                              .000     2.089    2.083    2.073                                    6  2.000   2.132                                                                               2.119                                                                              .000     2.123    2.113                                    7  1.700   2.170    2.167                                                                               2.167                                                                              .000     2.149                                    8  1.500   2.204    2.200    2.192                                                                               2.163                                                                              .000                                     __________________________________________________________________________     POS                                                                               R   bf  l    bf  l    bf  l    bf  l                                        __________________________________________________________________________     1  .000                                                                               -16.67                                                                             -260.62                                                                             -21.23                                                                             -289.47                                                                             -25.38                                                                             -257.96                                                                             -29.15                                                                             -287.02                                  2  10.000                                                                             -12.95                                                                             -256.29                                                                             -17.60                                                                             -293.84                                                                             -21.83                                                                             -256.64                                                                             -25.68                                                                             -291.50                                  3  5.000                                                                              -8.95                                                                              -248.44                                                                             -13.69                                                                             -301.29                                                                             -18.01                                                                             -254.61                                                                             -21.95                                                                             -298.05                                  4  3.500                                                                              -5.28                                                                              -233.20                                                                             -10.10                                                                             -313.17                                                                             -14.50                                                                             -251.63                                                                             -18.52                                                                             -306.54                                  5  2.500                                                                              .00 .00  -4.93                                                                              -349.85                                                                             -9.44                                                                              -241.50                                                                             -13.57                                                                             -326.01                                  6  2.000                                                                              5.03                                                                               -406.30                                                                             .00 .00  -4.61                                                                              -226.92                                                                             -8.84                                                                              -382.46                                  7  1.700                                                                              9.84                                                                               -325.37                                                                             4.71                                                                               -205.90                                                                             .00 .00  -4.32                                                                              -661.82                                  8  1.500                                                                              14.42                                                                              -311.67                                                                             9.21                                                                               -238.60                                                                             4.41                                                                               -379.51                                                                             .00 .00                                      __________________________________________________________________________      Condition Corresponding Values: K.sub.a0 /γ.sub.a0 = 1.11, K.sub.aR      /γ.sub.aR = 0.90                                                   

The calculation results of the rate of change of K_(a) with respect to γ_(a) at the infinity in-focus arrangement and the closest in-focus arrangement at the wide-angle end, middle position, and telephoto end in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and in the fifth embodiment of the present invention are as follows.

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement                                                                       Closest Arrangement                                                K.sub.aO /γ.sub.aO                                                                   K.sub.aK /γ.sub.aK                                  ______________________________________                                         Wide-angle End                                                                            2.75          0.44                                                  (F = 36.0)                                                                     Middle Position                                                                           3.36          0.43                                                  (F = 50.0)                                                                     Telephoto End                                                                             3.80          0.43                                                  (F = 103.0)                                                                    Fifth embodiment                                                               Wide-angle End                                                                            0.97          1.03                                                  (F = 81.5)                                                                     Middle Position                                                                           0.99          0.99                                                  (F = 135.0)                                                                    Telephoto End                                                                             1.11          0.90                                                  (F = 196.0)                                                                    ______________________________________                                    

As described above, in the fifth embodiment as well, since the rate of change of K_(a) with respect to γ_(a) is small as compared to the conventional system, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced. For this reason, an error of the conversion coefficient K_(a) calculated based on γ_(a) and μ or an error from the actual lens driving amount Δa obtained when only one pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set can be reduced.

Next, in the embodiment of Japanese Patent Application Laid-Open No. 5-142475 and the fifth embodiment of the present invention, when the lens driving amounts upon focusing from the infinity in-focus lens arrangement to the closest distance object and upon focusing from the closest in-focus lens arrangement to the infinity object at the wide-angle end, middle position, and telephoto end are calculated from Δa=ΔBf/ γ_(a) (1-ΔBf/μ)!, and errors from the actual lens driving amounts are then calculated, the following values are obtained. Note that the value of the correction coefficient μ upon focusing from the infinity in-focus lens arrangement to the closest distance object adopts a value at the object distance (POS-5), and the value of the correction coefficient μ upon focusing from the closest in-focus lens arrangement to the infinity object adopts a value at the object distance (POS-4).

    ______________________________________                                         Embodiment of Japanese Patent Application Laid-Open No. 5-142475                        Infinity Arrangement →                                                               Closest Arrangement →                                      Closest In-focus State                                                                      Infinity In-focus State                                  ______________________________________                                         Wide-angle End                                                                            -4.4%          -13.0%                                               (F = 36.0)                                                                     Middle Position                                                                           -11.8%         -12.0%                                               (F = 50.0)                                                                     Telephoto End                                                                             -12.6%         -14.6%                                               (F = 103.0)                                                                    Fifth embodiment                                                               Wide-angle End                                                                            0.1%           0.0%                                                 (F = 81.5)                                                                     Middle Position                                                                           0.1%           0.0%                                                 (F = 135.0)                                                                    Telephoto End                                                                             -0.3%          -0.7%                                                (F = 196.0)                                                                    ______________________________________                                    

As described above, in the fifth embodiment as well, even when only a pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a given lens arrangement range, an error between the conversion coefficient K_(a) calculated from γ_(a) and μ and the lens driving amount Δa for focusing becomes small as compared to the conventional system, and focusing can be realized with higher accuracy.

Table 54 summarizes the amount (ANGLE DA) of rotation for focusing upon manual focusing using the focus cam (the middle table in Table 46) of the fifth embodiment, the amount DX (mm) of movement, in the direction of the optical axis, of the focusing lens unit corresponding to the amount of rotation for focusing, and the displacement amount Bf (mm) of the imaging point when the amount (DX) of movement in the direction of the optical axis is given.

Note that the arrangement of the table and reference symbols are the same as those in the first embodiment. The upper table in Table 54 summarizes the displacement amount (Bf) of the imaging point corresponding to the photographing distances (R=5.0, 3.5, 2.5, 2.0, 1.7, and 1.5 m) in the respective zooming states of the focal lengths (F=81.5, 105.0, 135.0, 150.0, and 196.0 mm), and the middle table summarizes the values of the amount (ANGLE DA) of rotation for focusing required for attaining an optimal in-focus state with respect to the respective photographing distances. The lower table summarizes the amounts (DX) of movement, in the direction of the optical axis, of the respective lens units corresponding to the amount (ANGLE DA) of rotation for focusing in association with the focal lengths and photographing distances.

                                      TABLE 54                                     __________________________________________________________________________     Displacement Amount Bf (mm) of Imaging Point and Amount DX                     (mm) of movement for focusing in Fifth Embodiment                                         1.50 m                                                                              1.70 m                                                                             2.00 m                                                                              2.50 m                                                                             3.50 m                                                                              5.00 m                                       __________________________________________________________________________     F  81.500                                                                             Bf  .000 .000                                                                               .000 .000                                                                               .000 .000                                         F  105.000                                                                            Bf  -.011                                                                               -.013                                                                              -.012                                                                               -.008                                                                              -.005                                                                               -.003                                        F  135.000                                                                            Bf  .015 .021                                                                               .012 .009                                                                               .005 .001                                         F  150.000                                                                            Bf  -.011                                                                               -.015                                                                              -.006                                                                               -.010                                                                              -.010                                                                               -.010                                        F  196.000                                                                            Bf  .000 .000                                                                               .000 .000                                                                               .000 .000                                            ANGLE                                                                              DA  15.000                                                                              12.988                                                                             10.815                                                                              8.455                                                                              5.889                                                                               4.046                                        F  81.500                                                                             DX  .000 -13.544                                                                            .000 .000                                                                               R    1.50 m                                       F  105.000                                                                            DX  .000 -13.872                                                                            .000 .000                                                                               R    1.50 m                                       F  135.000                                                                            DX  .000 -14.400                                                                            .000 .000                                                                               R    1.50 m                                       F  150.000                                                                            DX  .000 -14.700                                                                            .000 .000                                                                               R    1.50 m                                       F  196.000                                                                            DX  .000 -15.450                                                                            .000 .000                                                                               R    1.50 m                                       F  81.500                                                                             DX  .000 -11.572                                                                            .000 .000                                                                               R    1.70 m                                       F  105.000                                                                            DX  .000 -11.856                                                                            .000 .000                                                                               R    1.70 m                                       F  135.000                                                                            DX  .000 -12.291                                                                            .000 .000                                                                               R    1.70 m                                       F  150.000                                                                            DX  .000 -12.559                                                                            .000 .000                                                                               R    1.70 m                                       F  196.000                                                                            DX  .000 -13.187                                                                            .000 .000                                                                               R    1.70 m                                       F  81.500                                                                             DX  .000 -9.497                                                                             .000 .000                                                                               R    2.00 m                                       F  105.000                                                                            DX  .000 -9.732                                                                             .000 .000                                                                               R    2.00 m                                       F  135.000                                                                            DX  .000 -10.089                                                                            .000 .000                                                                               R    2.00 m                                       F  150.000                                                                            DX  .000 -10.297                                                                            .000 .000                                                                               R    2.00 m                                       F  196.000                                                                            DX  .000 -10.812                                                                            .000 .000                                                                               R    2.00 m                                       F  81.500                                                                             DX  .000 -7.312                                                                             .000 .000                                                                               R    2.50 m                                       F  105.000                                                                            DX  .000 -7.491                                                                             .000 .000                                                                               R    2.50 m                                       F  135.000                                                                            DX  .000 -7.766                                                                             .000 .000                                                                               R    2.50 m                                       F  150.000                                                                            DX  .000 -7.928                                                                             .000 .000                                                                               R    2.50 m                                       F  196.000                                                                            DX  .000 -8.316                                                                             .000 .000                                                                               R    2.50 m                                       F  81.500                                                                             DX  .000 -5.008                                                                             .000 .000                                                                               R    3.50 m                                       F  105.000                                                                            DX  .000 -5.129                                                                             .000 .000                                                                               R    3.50 m                                       F  135.000                                                                            DX  .000 -5.319                                                                             .000 .000                                                                               R    3.50 m                                       F  150.000                                                                            DX  .000 -5.430                                                                             .000 .000                                                                               R    3.50 m                                       F  196.000                                                                            DX  .000 -5.689                                                                             .000 .000                                                                               R    3.50 m                                       F  81.500                                                                             DX  .000 -3.401                                                                             .000 .000                                                                               R    5.00 m                                       F  105.000                                                                            DX  .000 -3.482                                                                             .000 .000                                                                               R    5.00 m                                       F  135.000                                                                            DX  .000 -3.613                                                                             .000 .000                                                                               R    5.00 m                                       F  150.000                                                                            DX  .000 -3.688                                                                             .000 .000                                                                               R    5.00 m                                       F  196.000                                                                            DX  .000 -3.860                                                                             .000 .000                                                                               R    5.00 m                                       __________________________________________________________________________

As can be seen from Table 54, in the zoom lens of the fifth embodiment, so-called manual focusing can be attained since the displacement amounts of the imaging point at the respective focal lengths and photographing distances are very small, and fall within the depth of focus independently of the zooming state and photographing distance.

As described above in the embodiments, the present invention can be applied to zoom lens systems based on various lens unit arrangements or focusing lens units.

As described above, according to the present invention, in an inner focusing type zoom lens which is attached to, e.g., an auto-focusing camera which has focus detection means, storage means, calculation means, and the like, the number of data of specific coefficients (e.g., the conversion coefficient γ_(a) and the correction coefficient μ) required for auto-focusing can be reduced as compared to the conventional system. Furthermore, an error upon calculation of the lens driving amount of the focusing lens unit using the stored specific coefficients in correspondence with the detected defocus amount can be reduced as compared to the conventional system.

In other words, when the arrangement of the present invention is adopted, since the rate of change of the conversion coefficient γ_(a) is reduced so much as compared to the conventional system, the number of data of the conversion coefficient γ_(a), the correction coefficient μ, and the like which are stored for calculating the lens driving amount for focusing can be reduced, and a cost reduction can be realized in terms of the storage capacity.

Furthermore, since the change in conversion coefficient K_(a) to the conversion coefficient γ_(a) becomes small, the contribution of the correction term (ΔBf/μ) in K_(a) =γ_(a) (1-ΔBf/μ) can be reduced.

Therefore, an error of the conversion coefficient K_(a) calculated based on γ_(a) and μ or an error from the actual lens driving amount Δa obtained when only one pair of a conversion coefficient γ_(a) value and a correction coefficient μ value are set for a certain lens arrangement range can be reduced.

In the present invention, the conversion coefficient γ_(a) at an in-focus point and the conversion coefficient μ which is defined by formula K_(a) =γ_(a) (1-ΔBf/μ) are set to be specific coefficients. Alternatively, a correction coefficient defined by a formula different from the above-mentioned formula may be set. Furthermore, the conversion coefficient γ_(a) need not always be set in correspondence with the sensitivity (dBf/da) associated with the direction of rotation at an in-focus point. As long as focusing accuracy can be improved, the sensitivity at a point other than the in-focus point and the corresponding correction coefficient may be set to be specific coefficients.

Note that the present invention can be applied to various other zoom lens systems based on lens unit arrangements or focusing lens units other than those in the above-mentioned embodiments, as a matter of course. 

What is claimed is:
 1. A zoom lens system in which a movement locus of a focusing lens unit is defined by synthesizing a focus cam and a zoom compensation cam so as to achieve an in-focus state by a substantially constant amount of rotation for an identical object distance independently of a zooming state upon expression of a predetermined movement locus for zooming by an amount of movement, in a direction of an optical axis, of lens units, and an angle of rotation of a rotatable lens barrel, wherein when ratios (dBf/dx) of an amount dBf of infinitesimal movement of an imaging plane to an amount dx of infinitesimal movement, in the direction of the optical axis, of said focusing lens unit at infinity and closest in-focus points are respectively represented by γ_(xO) and γ_(xR), amounts of movement, in the direction of the optical axis, of said focusing lens unit required for focusing from an infinity position to a closest distance position at a wide-angle end and a telephoto end are respectively represented by Δx_(WR) and Δx_(TR), and an amount of rotation of said focusing lens unit on said focus cam corresponding to zooming from the wide-angle end to the telephoto end and an amount of rotation corresponding to focusing from an infinity in-focus state to a closest in-focus state are respectively represented by a_(Z) and a_(F), said zoom lens satisfies the following conditional formulas at least at the telephoto end:

    0.60 <γ.sub.xR /γ.sub.xO <1.70

    0.50<Δx.sub.TR /Δx.sub.WR <2.00

    0.30<|a.sub.F /a.sub.Z |<2.50.


2. A zoom lens system according to claim 1, wherein when ratios (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane to an amount da of infinitesimal movement, in a direction of rotation, of said focusing lens unit on said focus cam at the infinity and closest in-focus points are respectively represented by γ_(aO) and γ_(aR), said zoom lens satisfies the following conditional formula at least at the wide-angle end and the telephoto end:

    0.50 <γ.sub.aR /γ.sub.aO <2.00.


3. A zoom lens system according to claim 2, wherein when conversion coefficients K_(a), which are expressed by K_(a) =ΔBf/Δa and are obtained when said focusing lens unit is located in lens arrangements corresponding to the infinity in-focus state and the closest in-focus state, are respectively represented by K_(aO) and K_(aR), said zoom lens satisfies the following conditional formulas at least at the wide-angle end and the telephoto end:

    0.70<K.sub.aO /γ.sub.aO <1.80

    0.60<K.sub.aR /γ.sub.aR <1.60

where ΔBf: the defocus amount between an imaging position of an object at an arbitrary position and a predetermined imaging point position Δa: the angle of rotation of said focusing lens unit on said focus cam required for attaining an in-focus state on the object.
 4. A zoom lens system according to claim 1, wherein when ratios (dBf/da) of the amount dBf of infinitesimal movement of the imaging plane to an amount da of infinitesimal movement, in a direction of rotation, of said focusing lens unit on said focus cam at the infinity and closest in-focus points are respectively represented by γ_(aO) and γ_(aR), and conversion coefficients K_(a), which are expressed by K_(a) =ΔBf/Δa and are obtained when said focusing lens unit is located in lens arrangements corresponding to the infinity in-focus state and the closest in-focus state, are respectively represented by K_(aO) and K_(aR), said zoom lens satisfies the following conditional formulas at least at the wide-angle end and the telephoto end:

    0.70<K.sub.aO /γ.sub.aO <1.80

    0.60<K.sub.aR /γ.sub.aR <1.60

where ΔBf: the defocus amount between an imaging position of an object at an arbitrary position and a predetermined imaging point position Δa: the angle of rotation of said focusing lens unit on said focus cam required for attaining an in-focus state on the object. 